BLE peripheral stops transmitting after PHY update with different txPhy and rxPhy

[khpeterson]

MSDK version 0959f1e (but no changes in Libraries/Cordio relative to today's origin/HEAD) running on a vanilla MAX32666FTHR connecting with a Qualcomm based BlueZ host (Particle Tachyon).

Details below but it appears that the MAX32666 requires txPhy == rxPhy when configuring/updating the PHY. I added error logging to lctrSlvConnTxCompletion but nothing logged, the transmitter just stops sending.

Is this a known constraint of the BB hardware? I found the BB_SYM_PHY_REQ config variable is unset and defaults to 0 but could easily be added to the MAX32666 specific config.mk. When txPhy == rxPhy (typically 2 for my test setup) there is no problem with PHY update continuity (except for the issue noted in #1497).

With a little extra logging:

diff --git a/Libraries/Cordio/controller/sources/ble/lctr/lctr_isr_conn.c b/Libraries/Cordio/controller/sources/ble/lctr/lctr_isr_conn.c
index 1184006db6..2c4e063abc 100644
--- a/Libraries/Cordio/controller/sources/ble/lctr/lctr_isr_conn.c
+++ b/Libraries/Cordio/controller/sources/ble/lctr/lctr_isr_conn.c
@@ -172,6 +172,7 @@ uint8_t *lctrProcessRxAck(lctrConnCtx_t *pCtx)
     return pNextRxBuf;
   }
 
+  LL_TRACE_INFO3("lctrProcessRxAck: RETRANSMIT, handle=%u, sn=%u, nesn=%u", LCTR_GET_CONN_HANDLE(pCtx), pCtx->rxHdr.sn, pCtx->txHdr.nesn);
   return NULL;
 }

The relevant console log snippet (TRACE=2) shows the host/central is stuck retransmitting after the PHY updates at eventCounter=572:

lctrSlvLlcpExecutePhyUpdateSm: handle=0, llcpState=IDLE, phyUpdState=0, event=2
>>> Data Path Tx Paused, handle=0 <<<
lctrSlvLlcpExecutePhyUpdateSm: handle=0, llcpState=BUSY, phyUpdState=3, event=6
>>> Data Path Tx Unpaused/Resumed, handle=0 <<<
lctrSlvLlcpExecutePhyUpdateSm: handle=0, llcpState=BUSY, phyUpdState=4, event=1
lctrSlvConnRxCompletion: BB failed with status=RX_TIMEOUT, handle=0, bleChan=17, eventCounter=570
>>> PHY updated, handle=0, eventCounter=572 <<<
txPhy=1, rxPhy=2
lctrSlvLlcpExecutePhyUpdateSm: handle=0, llcpState=BUSY, phyUpdState=5, event=4
### LlEvent ###  LL_PHY_UPDATE_IND, phy=1, handle=0, status=0
Ble got evt 70
DM_PHY_UPDATE_IND - RX: 2, TX: 1
lctrProcessRxAck: RETRANSMIT, handle=0, sn=1, nesn=230
lctrSlvConnRxCompletion: BB failed with status=RX_TIMEOUT, handle=0, bleChan=8, eventCounter=573
lctrProcessRxAck: RETRANSMIT, handle=0, sn=1, nesn=230
lctrSlvConnRxCompletion: BB failed with status=RX_TIMEOUT, handle=0, bleChan=27, eventCounter=574
lctrProcessRxAck: RETRANSMIT, handle=0, sn=1, nesn=230
lctrSlvConnRxCompletion: BB failed with status=RX_TIMEOUT, handle=0, bleChan=15, eventCounter=575
lctrSlvConnRxCompletion: BB failed with status=CRC_FAILED, handle=0, bleChan=21, eventCounter=576
lctrProcessRxAck: RETRANSMIT, handle=0, sn=1, nesn=230
lctrSlvConnRxCompletion: BB failed with status=RX_TIMEOUT, handle=0, bleChan=27, eventCounter=577
lctrProcessRxAck: RETRANSMIT, handle=0, sn=1, nesn=230
lctrSlvConnRxCompletion: BB failed with status=RX_TIMEOUT, handle=0, bleChan=20, eventCounter=578
lctrProcessRxAck: RETRANSMIT, handle=0, sn=1, nesn=230
lctrSlvConnRxCompletion: BB failed with status=RX_TIMEOUT, handle=0, bleChan=33, eventCounter=579
lctrProcessRxAck: RETRANSMIT, handle=0, sn=1, nesn=230
lctrSlvConnRxCompletion: BB failed with status=RX_TIMEOUT, handle=0, bleChan=35, eventCounter=580
lctrProcessRxAck: RETRANSMIT, handle=0, sn=1, nesn=230
lctrSlvConnRxCompletion: BB failed with status=RX_TIMEOUT, handle=0, bleChan=25, eventCounter=581

And a Wireshark capture of the same sequence shows that the peripheral transmits its last packet at Frame 1070/event counter=571, just before the PHY is updated:

Frame 1048: Packet, 29 bytes on wire (232 bits), 29 bytes captured (232 bits) on interface COM10-4.6, id 0
nRF Sniffer for Bluetooth LE
    Board: 10
    Header Version: 3, Packet counter: 43362
    Length of packet: 10
    Flags: 0x13
        .... ...1 = CRC: Ok
        .... ..1. = Direction: Central -> Peripheral
        .... .0.. = Encrypted: No
        .... 0... = MIC (not relevant): 0
        .001 .... = PHY: LE 2M (1)
        0... .... = Reserved: 0
    Channel Index: 2
    RSSI: -46 dBm
    Event counter: 560
    Timestamp: 2865809669µs
    [Packet time (start to end): 56µs]
    [Delta time (end to start): 29762µs]
    [Delta time (start to start): 29806µs]
Bluetooth Low Energy Link Layer
    Access Address: 0x78c6e73a
    [Central Address: QuectelWirel_08:68:dc (24:19:72:08:68:dc)]
    [Peripheral Address: MaximIntegra_ff:9e:b1 (00:18:80:ff:9e:b1)]
    Data Header
        .... ..11 = LLID: Control PDU (0x3)
        .... .0.. = Next Expected Sequence Number: 0 [ACK]
        .... 0... = Sequence Number: 0 [OK]
        ...0 .... = More Data: False
        ..0. .... = CTE Info: Not Present
        00.. .... = RFU: 0
        Length: 3
    Control Opcode: LL_PHY_REQ (0x16)
    TX PHYs: 0x07, Sender prefers to use the LE 1M PHY, Sender prefers to use the LE 2M PHY, Sender prefers to use the LE Coded PHY
    RX PHYs: 0x01, Sender prefers to use the LE 1M PHY
    [Response in Frame: 1053]
    [Response in Frame: 1054]
    [Connection Parameters in: 2]
    CRC: 0xe08002

Frame 1049: Packet, 198 bytes on wire (1584 bits), 198 bytes captured (1584 bits) on interface COM10-4.6, id 0
nRF Sniffer for Bluetooth LE
    Board: 10
    Header Version: 3, Packet counter: 43363
    Length of packet: 10
    Flags: 0x11
        .... ...1 = CRC: Ok
        .... ..0. = Direction: Peripheral -> Central
        .... .0.. = Encrypted: No
        .... 0... = MIC (not relevant): 0
        .001 .... = PHY: LE 2M (1)
        0... .... = Reserved: 0
    Channel Index: 2
    RSSI: -47 dBm
    Event counter: 560
    Timestamp: 2865809875µs
    [Packet time (start to end): 732µs]
    [Delta time (end to start): 150µs]
    [Delta time (start to start): 206µs]
Bluetooth Low Energy Link Layer
    Access Address: 0x78c6e73a
    [Central Address: QuectelWirel_08:68:dc (24:19:72:08:68:dc)]
    [Peripheral Address: MaximIntegra_ff:9e:b1 (00:18:80:ff:9e:b1)]
    Data Header
        .... ..10 = LLID: Start of an L2CAP message or a complete L2CAP message with no fragmentation (0x2)
        .... .1.. = Next Expected Sequence Number: 1 [ACK]
        .... 0... = Sequence Number: 0 [OK]
        ...0 .... = More Data: False
        ..0. .... = CTE Info: Not Present
        00.. .... = RFU: 0
        Length: 172
    [L2CAP Index: 40]
    [Connection Parameters in: 2]
    CRC: 0x2bc22d
Bluetooth L2CAP Protocol
Bluetooth Attribute Protocol

Frame 1050: Packet, 26 bytes on wire (208 bits), 26 bytes captured (208 bits) on interface COM10-4.6, id 0
nRF Sniffer for Bluetooth LE
    Board: 10
    Header Version: 3, Packet counter: 43364
    Length of packet: 10
    Flags: 0x1b
        .... ...1 = CRC: Ok
        .... ..1. = Direction: Central -> Peripheral
        .... .0.. = Encrypted: No
        .... 1... = MIC (not relevant): 1
        .001 .... = PHY: LE 2M (1)
        0... .... = Reserved: 0
    Channel Index: 11
    RSSI: -49 dBm
    Event counter: 561
    Timestamp: 2865839670µs
    [Packet time (start to end): 44µs]
    [Delta time (end to start): 29063µs]
    [Delta time (start to start): 29795µs]
Bluetooth Low Energy Link Layer
    Access Address: 0x78c6e73a
    [Central Address: QuectelWirel_08:68:dc (24:19:72:08:68:dc)]
    [Peripheral Address: MaximIntegra_ff:9e:b1 (00:18:80:ff:9e:b1)]
    Data Header
        .... ..01 = LLID: Continuation fragment of an L2CAP message, or an Empty PDU (0x1)
        .... .1.. = Next Expected Sequence Number: 1 [ACK]
        .... 1... = Sequence Number: 1 [OK]
        ...0 .... = More Data: False
        ..0. .... = CTE Info: Not Present
        00.. .... = RFU: 0
        Length: 0
    [Connection Parameters in: 2]
    CRC: 0xffba11

Frame 1051: Packet, 26 bytes on wire (208 bits), 26 bytes captured (208 bits) on interface COM10-4.6, id 0
nRF Sniffer for Bluetooth LE
    Board: 10
    Header Version: 3, Packet counter: 43365
    Length of packet: 10
    Flags: 0x19
        .... ...1 = CRC: Ok
        .... ..0. = Direction: Peripheral -> Central
        .... .0.. = Encrypted: No
        .... 1... = MIC (not relevant): 1
        .001 .... = PHY: LE 2M (1)
        0... .... = Reserved: 0
    Channel Index: 11
    RSSI: -46 dBm
    Event counter: 561
    Timestamp: 2865839864µs
    [Packet time (start to end): 44µs]
    [Delta time (end to start): 150µs]
    [Delta time (start to start): 194µs]
Bluetooth Low Energy Link Layer
    Access Address: 0x78c6e73a
    [Central Address: QuectelWirel_08:68:dc (24:19:72:08:68:dc)]
    [Peripheral Address: MaximIntegra_ff:9e:b1 (00:18:80:ff:9e:b1)]
    Data Header
        .... ..01 = LLID: Continuation fragment of an L2CAP message, or an Empty PDU (0x1)
        .... .0.. = Next Expected Sequence Number: 0 [ACK]
        .... 1... = Sequence Number: 1 [OK]
        ...0 .... = More Data: False
        ..0. .... = CTE Info: Not Present
        00.. .... = RFU: 0
        Length: 0
    [Connection Parameters in: 2]
    CRC: 0x34da11

Frame 1052: Packet, 26 bytes on wire (208 bits), 26 bytes captured (208 bits) on interface COM10-4.6, id 0
nRF Sniffer for Bluetooth LE
    Board: 10
    Header Version: 3, Packet counter: 43366
    Length of packet: 10
    Flags: 0x1b
        .... ...1 = CRC: Ok
        .... ..1. = Direction: Central -> Peripheral
        .... .0.. = Encrypted: No
        .... 1... = MIC (not relevant): 1
        .001 .... = PHY: LE 2M (1)
        0... .... = Reserved: 0
    Channel Index: 4
    RSSI: -47 dBm
    Event counter: 562
    Timestamp: 2865869671µs
    [Packet time (start to end): 44µs]
    [Delta time (end to start): 29763µs]
    [Delta time (start to start): 29807µs]
Bluetooth Low Energy Link Layer
    Access Address: 0x78c6e73a
    [Central Address: QuectelWirel_08:68:dc (24:19:72:08:68:dc)]
    [Peripheral Address: MaximIntegra_ff:9e:b1 (00:18:80:ff:9e:b1)]
    Data Header
        .... ..01 = LLID: Continuation fragment of an L2CAP message, or an Empty PDU (0x1)
        .... .0.. = Next Expected Sequence Number: 0 [ACK]
        .... 0... = Sequence Number: 0 [OK]
        ...0 .... = More Data: False
        ..0. .... = CTE Info: Not Present
        00.. .... = RFU: 0
        Length: 0
    [Connection Parameters in: 2]
    CRC: 0x516a11

Frame 1053: Packet, 29 bytes on wire (232 bits), 29 bytes captured (232 bits) on interface COM10-4.6, id 0
nRF Sniffer for Bluetooth LE
    Board: 10
    Header Version: 3, Packet counter: 43367
    Length of packet: 10
    Flags: 0x11
        .... ...1 = CRC: Ok
        .... ..0. = Direction: Peripheral -> Central
        .... .0.. = Encrypted: No
        .... 0... = MIC (not relevant): 0
        .001 .... = PHY: LE 2M (1)
        0... .... = Reserved: 0
    Channel Index: 4
    RSSI: -46 dBm
    Event counter: 562
    Timestamp: 2865869865µs
    [Packet time (start to end): 56µs]
    [Delta time (end to start): 150µs]
    [Delta time (start to start): 194µs]
Bluetooth Low Energy Link Layer
    Access Address: 0x78c6e73a
    [Central Address: QuectelWirel_08:68:dc (24:19:72:08:68:dc)]
    [Peripheral Address: MaximIntegra_ff:9e:b1 (00:18:80:ff:9e:b1)]
    Data Header
        .... ..11 = LLID: Control PDU (0x3)
        .... .1.. = Next Expected Sequence Number: 1 [ACK]
        .... 0... = Sequence Number: 0 [OK]
        ...0 .... = More Data: False
        ..0. .... = CTE Info: Not Present
        00.. .... = RFU: 0
        Length: 3
    Control Opcode: LL_PHY_RSP (0x17)
    TX PHYs: 0x07, Sender prefers to use the LE 1M PHY, Sender prefers to use the LE 2M PHY, Sender prefers to use the LE Coded PHY
    RX PHYs: 0x07, Sender prefers to use the LE 1M PHY, Sender prefers to use the LE 2M PHY, Sender prefers to use the LE Coded PHY
    [Request in Frame: 1048]
    [Connection Parameters in: 2]
    CRC: 0xe0e0ae

Frame 1054: Packet, 31 bytes on wire (248 bits), 31 bytes captured (248 bits) on interface COM10-4.6, id 0
nRF Sniffer for Bluetooth LE
    Board: 10
    Header Version: 3, Packet counter: 43368
    Length of packet: 10
    Flags: 0x13
        .... ...1 = CRC: Ok
        .... ..1. = Direction: Central -> Peripheral
        .... .0.. = Encrypted: No
        .... 0... = MIC (not relevant): 0
        .001 .... = PHY: LE 2M (1)
        0... .... = Reserved: 0
    Channel Index: 3
    RSSI: -46 dBm
    Event counter: 563
    Timestamp: 2865899672µs
    [Packet time (start to end): 64µs]
    [Delta time (end to start): 29751µs]
    [Delta time (start to start): 29807µs]
Bluetooth Low Energy Link Layer
    Access Address: 0x78c6e73a
    [Central Address: QuectelWirel_08:68:dc (24:19:72:08:68:dc)]
    [Peripheral Address: MaximIntegra_ff:9e:b1 (00:18:80:ff:9e:b1)]
    Data Header
        .... ..11 = LLID: Control PDU (0x3)
        .... .1.. = Next Expected Sequence Number: 1 [ACK]
        .... 1... = Sequence Number: 1 [OK]
        ...0 .... = More Data: False
        ..0. .... = CTE Info: Not Present
        00.. .... = RFU: 0
        Length: 5
    Control Opcode: LL_PHY_UPDATE_IND (0x18)
    Central to Peripheral PHY: 0x00, No change
    Peripheral to Central PHY: 0x01, The LE 1M PHY shall be used
    Reserved for future use: 572
    [Request in Frame: 1048]
    [Connection Parameters in: 2]
    CRC: 0x116f59

Frame 1055: Packet, 26 bytes on wire (208 bits), 26 bytes captured (208 bits) on interface COM10-4.6, id 0
nRF Sniffer for Bluetooth LE
    Board: 10
    Header Version: 3, Packet counter: 43369
    Length of packet: 10
    Flags: 0x19
        .... ...1 = CRC: Ok
        .... ..0. = Direction: Peripheral -> Central
        .... .0.. = Encrypted: No
        .... 1... = MIC (not relevant): 1
        .001 .... = PHY: LE 2M (1)
        0... .... = Reserved: 0
    Channel Index: 3
    RSSI: -46 dBm
    Event counter: 563
    Timestamp: 2865899886µs
    [Packet time (start to end): 44µs]
    [Delta time (end to start): 150µs]
    [Delta time (start to start): 214µs]
Bluetooth Low Energy Link Layer
    Access Address: 0x78c6e73a
    [Central Address: QuectelWirel_08:68:dc (24:19:72:08:68:dc)]
    [Peripheral Address: MaximIntegra_ff:9e:b1 (00:18:80:ff:9e:b1)]
    Data Header
        .... ..01 = LLID: Continuation fragment of an L2CAP message, or an Empty PDU (0x1)
        .... .0.. = Next Expected Sequence Number: 0 [ACK]
        .... 1... = Sequence Number: 1 [OK]
        ...0 .... = More Data: False
        ..0. .... = CTE Info: Not Present
        00.. .... = RFU: 0
        Length: 0
    [Connection Parameters in: 2]
    CRC: 0x34da11

Frame 1056: Packet, 26 bytes on wire (208 bits), 26 bytes captured (208 bits) on interface COM10-4.6, id 0
nRF Sniffer for Bluetooth LE
    Board: 10
    Header Version: 3, Packet counter: 43370
    Length of packet: 10
    Flags: 0x1b
        .... ...1 = CRC: Ok
        .... ..1. = Direction: Central -> Peripheral
        .... .0.. = Encrypted: No
        .... 1... = MIC (not relevant): 1
        .001 .... = PHY: LE 2M (1)
        0... .... = Reserved: 0
    Channel Index: 4
    RSSI: -46 dBm
    Event counter: 564
    Timestamp: 2865929673µs
    [Packet time (start to end): 44µs]
    [Delta time (end to start): 29743µs]
    [Delta time (start to start): 29787µs]
Bluetooth Low Energy Link Layer
    Access Address: 0x78c6e73a
    [Central Address: QuectelWirel_08:68:dc (24:19:72:08:68:dc)]
    [Peripheral Address: MaximIntegra_ff:9e:b1 (00:18:80:ff:9e:b1)]
    Data Header
        .... ..01 = LLID: Continuation fragment of an L2CAP message, or an Empty PDU (0x1)
        .... .0.. = Next Expected Sequence Number: 0 [ACK]
        .... 0... = Sequence Number: 0 [OK]
        ...0 .... = More Data: False
        ..0. .... = CTE Info: Not Present
        00.. .... = RFU: 0
        Length: 0
    [Connection Parameters in: 2]
    CRC: 0x516a11

Frame 1057: Packet, 26 bytes on wire (208 bits), 26 bytes captured (208 bits) on interface COM10-4.6, id 0
nRF Sniffer for Bluetooth LE
    Board: 10
    Header Version: 3, Packet counter: 43371
    Length of packet: 10
    Flags: 0x19
        .... ...1 = CRC: Ok
        .... ..0. = Direction: Peripheral -> Central
        .... .0.. = Encrypted: No
        .... 1... = MIC (not relevant): 1
        .001 .... = PHY: LE 2M (1)
        0... .... = Reserved: 0
    Channel Index: 4
    RSSI: -46 dBm
    Event counter: 564
    Timestamp: 2865929867µs
    [Packet time (start to end): 44µs]
    [Delta time (end to start): 150µs]
    [Delta time (start to start): 194µs]
Bluetooth Low Energy Link Layer
    Access Address: 0x78c6e73a
    [Central Address: QuectelWirel_08:68:dc (24:19:72:08:68:dc)]
    [Peripheral Address: MaximIntegra_ff:9e:b1 (00:18:80:ff:9e:b1)]
    Data Header
        .... ..01 = LLID: Continuation fragment of an L2CAP message, or an Empty PDU (0x1)
        .... .1.. = Next Expected Sequence Number: 1 [ACK]
        .... 0... = Sequence Number: 0 [OK]
        ...0 .... = More Data: False
        ..0. .... = CTE Info: Not Present
        00.. .... = RFU: 0
        Length: 0
    [Connection Parameters in: 2]
    CRC: 0x9a0a11

Frame 1058: Packet, 26 bytes on wire (208 bits), 26 bytes captured (208 bits) on interface COM10-4.6, id 0
nRF Sniffer for Bluetooth LE
    Board: 10
    Header Version: 3, Packet counter: 43372
    Length of packet: 10
    Flags: 0x1b
        .... ...1 = CRC: Ok
        .... ..1. = Direction: Central -> Peripheral
        .... .0.. = Encrypted: No
        .... 1... = MIC (not relevant): 1
        .001 .... = PHY: LE 2M (1)
        0... .... = Reserved: 0
    Channel Index: 8
    RSSI: -47 dBm
    Event counter: 565
    Timestamp: 2865959674µs
    [Packet time (start to end): 44µs]
    [Delta time (end to start): 29763µs]
    [Delta time (start to start): 29807µs]
Bluetooth Low Energy Link Layer
    Access Address: 0x78c6e73a
    [Central Address: QuectelWirel_08:68:dc (24:19:72:08:68:dc)]
    [Peripheral Address: MaximIntegra_ff:9e:b1 (00:18:80:ff:9e:b1)]
    Data Header
        .... ..01 = LLID: Continuation fragment of an L2CAP message, or an Empty PDU (0x1)
        .... .1.. = Next Expected Sequence Number: 1 [ACK]
        .... 1... = Sequence Number: 1 [OK]
        ...0 .... = More Data: False
        ..0. .... = CTE Info: Not Present
        00.. .... = RFU: 0
        Length: 0
    [Connection Parameters in: 2]
    CRC: 0xffba11

Frame 1059: Packet, 26 bytes on wire (208 bits), 26 bytes captured (208 bits) on interface COM10-4.6, id 0
nRF Sniffer for Bluetooth LE
    Board: 10
    Header Version: 3, Packet counter: 43373
    Length of packet: 10
    Flags: 0x19
        .... ...1 = CRC: Ok
        .... ..0. = Direction: Peripheral -> Central
        .... .0.. = Encrypted: No
        .... 1... = MIC (not relevant): 1
        .001 .... = PHY: LE 2M (1)
        0... .... = Reserved: 0
    Channel Index: 8
    RSSI: -45 dBm
    Event counter: 565
    Timestamp: 2865959868µs
    [Packet time (start to end): 44µs]
    [Delta time (end to start): 150µs]
    [Delta time (start to start): 194µs]
Bluetooth Low Energy Link Layer
    Access Address: 0x78c6e73a
    [Central Address: QuectelWirel_08:68:dc (24:19:72:08:68:dc)]
    [Peripheral Address: MaximIntegra_ff:9e:b1 (00:18:80:ff:9e:b1)]
    Data Header
        .... ..01 = LLID: Continuation fragment of an L2CAP message, or an Empty PDU (0x1)
        .... .0.. = Next Expected Sequence Number: 0 [ACK]
        .... 1... = Sequence Number: 1 [OK]
        ...0 .... = More Data: False
        ..0. .... = CTE Info: Not Present
        00.. .... = RFU: 0
        Length: 0
    [Connection Parameters in: 2]
    CRC: 0x34da11

Frame 1060: Packet, 26 bytes on wire (208 bits), 26 bytes captured (208 bits) on interface COM10-4.6, id 0
nRF Sniffer for Bluetooth LE
    Board: 10
    Header Version: 3, Packet counter: 43374
    Length of packet: 10
    Flags: 0x1b
        .... ...1 = CRC: Ok
        .... ..1. = Direction: Central -> Peripheral
        .... .0.. = Encrypted: No
        .... 1... = MIC (not relevant): 1
        .001 .... = PHY: LE 2M (1)
        0... .... = Reserved: 0
    Channel Index: 15
    RSSI: -52 dBm
    Event counter: 566
    Timestamp: 2865989675µs
    [Packet time (start to end): 44µs]
    [Delta time (end to start): 29763µs]
    [Delta time (start to start): 29807µs]
Bluetooth Low Energy Link Layer
    Access Address: 0x78c6e73a
    [Central Address: QuectelWirel_08:68:dc (24:19:72:08:68:dc)]
    [Peripheral Address: MaximIntegra_ff:9e:b1 (00:18:80:ff:9e:b1)]
    Data Header
        .... ..01 = LLID: Continuation fragment of an L2CAP message, or an Empty PDU (0x1)
        .... .0.. = Next Expected Sequence Number: 0 [ACK]
        .... 0... = Sequence Number: 0 [OK]
        ...0 .... = More Data: False
        ..0. .... = CTE Info: Not Present
        00.. .... = RFU: 0
        Length: 0
    [Connection Parameters in: 2]
    CRC: 0x516a11

Frame 1061: Packet, 26 bytes on wire (208 bits), 26 bytes captured (208 bits) on interface COM10-4.6, id 0
nRF Sniffer for Bluetooth LE
    Board: 10
    Header Version: 3, Packet counter: 43375
    Length of packet: 10
    Flags: 0x19
        .... ...1 = CRC: Ok
        .... ..0. = Direction: Peripheral -> Central
        .... .0.. = Encrypted: No
        .... 1... = MIC (not relevant): 1
        .001 .... = PHY: LE 2M (1)
        0... .... = Reserved: 0
    Channel Index: 15
    RSSI: -47 dBm
    Event counter: 566
    Timestamp: 2865989869µs
    [Packet time (start to end): 44µs]
    [Delta time (end to start): 150µs]
    [Delta time (start to start): 194µs]
Bluetooth Low Energy Link Layer
    Access Address: 0x78c6e73a
    [Central Address: QuectelWirel_08:68:dc (24:19:72:08:68:dc)]
    [Peripheral Address: MaximIntegra_ff:9e:b1 (00:18:80:ff:9e:b1)]
    Data Header
        .... ..01 = LLID: Continuation fragment of an L2CAP message, or an Empty PDU (0x1)
        .... .1.. = Next Expected Sequence Number: 1 [ACK]
        .... 0... = Sequence Number: 0 [OK]
        ...0 .... = More Data: False
        ..0. .... = CTE Info: Not Present
        00.. .... = RFU: 0
        Length: 0
    [Connection Parameters in: 2]
    CRC: 0x9a0a11

Frame 1062: Packet, 26 bytes on wire (208 bits), 26 bytes captured (208 bits) on interface COM10-4.6, id 0
nRF Sniffer for Bluetooth LE
    Board: 10
    Header Version: 3, Packet counter: 43376
    Length of packet: 10
    Flags: 0x1b
        .... ...1 = CRC: Ok
        .... ..1. = Direction: Central -> Peripheral
        .... .0.. = Encrypted: No
        .... 1... = MIC (not relevant): 1
        .001 .... = PHY: LE 2M (1)
        0... .... = Reserved: 0
    Channel Index: 3
    RSSI: -46 dBm
    Event counter: 567
    Timestamp: 2866019676µs
    [Packet time (start to end): 44µs]
    [Delta time (end to start): 29763µs]
    [Delta time (start to start): 29807µs]
Bluetooth Low Energy Link Layer
    Access Address: 0x78c6e73a
    [Central Address: QuectelWirel_08:68:dc (24:19:72:08:68:dc)]
    [Peripheral Address: MaximIntegra_ff:9e:b1 (00:18:80:ff:9e:b1)]
    Data Header
        .... ..01 = LLID: Continuation fragment of an L2CAP message, or an Empty PDU (0x1)
        .... .1.. = Next Expected Sequence Number: 1 [ACK]
        .... 1... = Sequence Number: 1 [OK]
        ...0 .... = More Data: False
        ..0. .... = CTE Info: Not Present
        00.. .... = RFU: 0
        Length: 0
    [Connection Parameters in: 2]
    CRC: 0xffba11

Frame 1063: Packet, 26 bytes on wire (208 bits), 26 bytes captured (208 bits) on interface COM10-4.6, id 0
nRF Sniffer for Bluetooth LE
    Board: 10
    Header Version: 3, Packet counter: 43377
    Length of packet: 10
    Flags: 0x19
        .... ...1 = CRC: Ok
        .... ..0. = Direction: Peripheral -> Central
        .... .0.. = Encrypted: No
        .... 1... = MIC (not relevant): 1
        .001 .... = PHY: LE 2M (1)
        0... .... = Reserved: 0
    Channel Index: 3
    RSSI: -46 dBm
    Event counter: 567
    Timestamp: 2866019870µs
    [Packet time (start to end): 44µs]
    [Delta time (end to start): 150µs]
    [Delta time (start to start): 194µs]
Bluetooth Low Energy Link Layer
    Access Address: 0x78c6e73a
    [Central Address: QuectelWirel_08:68:dc (24:19:72:08:68:dc)]
    [Peripheral Address: MaximIntegra_ff:9e:b1 (00:18:80:ff:9e:b1)]
    Data Header
        .... ..01 = LLID: Continuation fragment of an L2CAP message, or an Empty PDU (0x1)
        .... .0.. = Next Expected Sequence Number: 0 [ACK]
        .... 1... = Sequence Number: 1 [OK]
        ...0 .... = More Data: False
        ..0. .... = CTE Info: Not Present
        00.. .... = RFU: 0
        Length: 0
    [Connection Parameters in: 2]
    CRC: 0x34da11

Frame 1064: Packet, 26 bytes on wire (208 bits), 26 bytes captured (208 bits) on interface COM10-4.6, id 0
nRF Sniffer for Bluetooth LE
    Board: 10
    Header Version: 3, Packet counter: 43378
    Length of packet: 10
    Flags: 0x1b
        .... ...1 = CRC: Ok
        .... ..1. = Direction: Central -> Peripheral
        .... .0.. = Encrypted: No
        .... 1... = MIC (not relevant): 1
        .001 .... = PHY: LE 2M (1)
        0... .... = Reserved: 0
    Channel Index: 32
    RSSI: -57 dBm
    Event counter: 568
    Timestamp: 2866049677µs
    [Packet time (start to end): 44µs]
    [Delta time (end to start): 29763µs]
    [Delta time (start to start): 29807µs]
Bluetooth Low Energy Link Layer
    Access Address: 0x78c6e73a
    [Central Address: QuectelWirel_08:68:dc (24:19:72:08:68:dc)]
    [Peripheral Address: MaximIntegra_ff:9e:b1 (00:18:80:ff:9e:b1)]
    Data Header
        .... ..01 = LLID: Continuation fragment of an L2CAP message, or an Empty PDU (0x1)
        .... .0.. = Next Expected Sequence Number: 0 [ACK]
        .... 0... = Sequence Number: 0 [OK]
        ...0 .... = More Data: False
        ..0. .... = CTE Info: Not Present
        00.. .... = RFU: 0
        Length: 0
    [Connection Parameters in: 2]
    CRC: 0x516a11

Frame 1065: Packet, 26 bytes on wire (208 bits), 26 bytes captured (208 bits) on interface COM10-4.6, id 0
nRF Sniffer for Bluetooth LE
    Board: 10
    Header Version: 3, Packet counter: 43379
    Length of packet: 10
    Flags: 0x19
        .... ...1 = CRC: Ok
        .... ..0. = Direction: Peripheral -> Central
        .... .0.. = Encrypted: No
        .... 1... = MIC (not relevant): 1
        .001 .... = PHY: LE 2M (1)
        0... .... = Reserved: 0
    Channel Index: 32
    RSSI: -52 dBm
    Event counter: 568
    Timestamp: 2866049871µs
    [Packet time (start to end): 44µs]
    [Delta time (end to start): 150µs]
    [Delta time (start to start): 194µs]
Bluetooth Low Energy Link Layer
    Access Address: 0x78c6e73a
    [Central Address: QuectelWirel_08:68:dc (24:19:72:08:68:dc)]
    [Peripheral Address: MaximIntegra_ff:9e:b1 (00:18:80:ff:9e:b1)]
    Data Header
        .... ..01 = LLID: Continuation fragment of an L2CAP message, or an Empty PDU (0x1)
        .... .1.. = Next Expected Sequence Number: 1 [ACK]
        .... 0... = Sequence Number: 0 [OK]
        ...0 .... = More Data: False
        ..0. .... = CTE Info: Not Present
        00.. .... = RFU: 0
        Length: 0
    [Connection Parameters in: 2]
    CRC: 0x9a0a11

Frame 1066: Packet, 26 bytes on wire (208 bits), 26 bytes captured (208 bits) on interface COM10-4.6, id 0
nRF Sniffer for Bluetooth LE
    Board: 10
    Header Version: 3, Packet counter: 43380
    Length of packet: 10
    Flags: 0x1b
        .... ...1 = CRC: Ok
        .... ..1. = Direction: Central -> Peripheral
        .... .0.. = Encrypted: No
        .... 1... = MIC (not relevant): 1
        .001 .... = PHY: LE 2M (1)
        0... .... = Reserved: 0
    Channel Index: 10
    RSSI: -48 dBm
    Event counter: 569
    Timestamp: 2866079678µs
    [Packet time (start to end): 44µs]
    [Delta time (end to start): 29763µs]
    [Delta time (start to start): 29807µs]
Bluetooth Low Energy Link Layer
    Access Address: 0x78c6e73a
    [Central Address: QuectelWirel_08:68:dc (24:19:72:08:68:dc)]
    [Peripheral Address: MaximIntegra_ff:9e:b1 (00:18:80:ff:9e:b1)]
    Data Header
        .... ..01 = LLID: Continuation fragment of an L2CAP message, or an Empty PDU (0x1)
        .... .1.. = Next Expected Sequence Number: 1 [ACK]
        .... 1... = Sequence Number: 1 [OK]
        ...0 .... = More Data: False
        ..0. .... = CTE Info: Not Present
        00.. .... = RFU: 0
        Length: 0
    [Connection Parameters in: 2]
    CRC: 0xffba11

Frame 1067: Packet, 26 bytes on wire (208 bits), 26 bytes captured (208 bits) on interface COM10-4.6, id 0
nRF Sniffer for Bluetooth LE
    Board: 10
    Header Version: 3, Packet counter: 43381
    Length of packet: 10
    Flags: 0x19
        .... ...1 = CRC: Ok
        .... ..0. = Direction: Peripheral -> Central
        .... .0.. = Encrypted: No
        .... 1... = MIC (not relevant): 1
        .001 .... = PHY: LE 2M (1)
        0... .... = Reserved: 0
    Channel Index: 10
    RSSI: -45 dBm
    Event counter: 569
    Timestamp: 2866079871µs
    [Packet time (start to end): 44µs]
    [Delta time (end to start): 149µs]
    [Delta time (start to start): 193µs]
Bluetooth Low Energy Link Layer
    Access Address: 0x78c6e73a
    [Central Address: QuectelWirel_08:68:dc (24:19:72:08:68:dc)]
    [Peripheral Address: MaximIntegra_ff:9e:b1 (00:18:80:ff:9e:b1)]
    Data Header
        .... ..01 = LLID: Continuation fragment of an L2CAP message, or an Empty PDU (0x1)
        .... .0.. = Next Expected Sequence Number: 0 [ACK]
        .... 1... = Sequence Number: 1 [OK]
        ...0 .... = More Data: False
        ..0. .... = CTE Info: Not Present
        00.. .... = RFU: 0
        Length: 0
    [Connection Parameters in: 2]
    CRC: 0x34da11

Frame 1068: Packet, 26 bytes on wire (208 bits), 26 bytes captured (208 bits) on interface COM10-4.6, id 0
nRF Sniffer for Bluetooth LE
    Board: 10
    Header Version: 3, Packet counter: 43382
    Length of packet: 10
    Flags: 0x1b
        .... ...1 = CRC: Ok
        .... ..1. = Direction: Central -> Peripheral
        .... .0.. = Encrypted: No
        .... 1... = MIC (not relevant): 1
        .001 .... = PHY: LE 2M (1)
        0... .... = Reserved: 0
    Channel Index: 17
    RSSI: -52 dBm
    Event counter: 570
    Timestamp: 2866109678µs
    [Packet time (start to end): 44µs]
    [Delta time (end to start): 29763µs]
    [Delta time (start to start): 29807µs]
Bluetooth Low Energy Link Layer
    Access Address: 0x78c6e73a
    [Central Address: QuectelWirel_08:68:dc (24:19:72:08:68:dc)]
    [Peripheral Address: MaximIntegra_ff:9e:b1 (00:18:80:ff:9e:b1)]
    Data Header
        .... ..01 = LLID: Continuation fragment of an L2CAP message, or an Empty PDU (0x1)
        .... .0.. = Next Expected Sequence Number: 0 [ACK]
        .... 0... = Sequence Number: 0 [OK]
        ...0 .... = More Data: False
        ..0. .... = CTE Info: Not Present
        00.. .... = RFU: 0
        Length: 0
    [Connection Parameters in: 2]
    CRC: 0x516a11

Frame 1069: Packet, 26 bytes on wire (208 bits), 26 bytes captured (208 bits) on interface COM10-4.6, id 0
nRF Sniffer for Bluetooth LE
    Board: 10
    Header Version: 3, Packet counter: 43383
    Length of packet: 10
    Flags: 0x1b
        .... ...1 = CRC: Ok
        .... ..1. = Direction: Central -> Peripheral
        .... .0.. = Encrypted: No
        .... 1... = MIC (not relevant): 1
        .001 .... = PHY: LE 2M (1)
        0... .... = Reserved: 0
    Channel Index: 21
    RSSI: -57 dBm
    Event counter: 571
    Timestamp: 2866139679µs
    [Packet time (start to end): 44µs]
    [Delta time (end to start): 29957µs]
    [Delta time (start to start): 30001µs]
Bluetooth Low Energy Link Layer
    Access Address: 0x78c6e73a
    [Central Address: QuectelWirel_08:68:dc (24:19:72:08:68:dc)]
    [Peripheral Address: MaximIntegra_ff:9e:b1 (00:18:80:ff:9e:b1)]
    Data Header
        .... ..01 = LLID: Continuation fragment of an L2CAP message, or an Empty PDU (0x1)
        .... .0.. = Next Expected Sequence Number: 0 [ACK]
        .... 0... = Sequence Number: 0 [Retransmit]
        ...0 .... = More Data: False
        ..0. .... = CTE Info: Not Present
        00.. .... = RFU: 0
        Length: 0
    [Connection Parameters in: 2]
    CRC: 0x516a11

Frame 1070: Packet, 26 bytes on wire (208 bits), 26 bytes captured (208 bits) on interface COM10-4.6, id 0
nRF Sniffer for Bluetooth LE
    Board: 10
    Header Version: 3, Packet counter: 43384
    Length of packet: 10
    Flags: 0x19
        .... ...1 = CRC: Ok
        .... ..0. = Direction: Peripheral -> Central
        .... .0.. = Encrypted: No
        .... 1... = MIC (not relevant): 1
        .001 .... = PHY: LE 2M (1)
        0... .... = Reserved: 0
    Channel Index: 21
    RSSI: -49 dBm
    Event counter: 571
    Timestamp: 2866139873µs
    [Packet time (start to end): 44µs]
    [Delta time (end to start): 150µs]
    [Delta time (start to start): 194µs]
Bluetooth Low Energy Link Layer
    Access Address: 0x78c6e73a
    [Central Address: QuectelWirel_08:68:dc (24:19:72:08:68:dc)]
    [Peripheral Address: MaximIntegra_ff:9e:b1 (00:18:80:ff:9e:b1)]
    Data Header
        .... ..01 = LLID: Continuation fragment of an L2CAP message, or an Empty PDU (0x1)
        .... .1.. = Next Expected Sequence Number: 1 [ACK]
        .... 0... = Sequence Number: 0 [OK]
        ...0 .... = More Data: False
        ..0. .... = CTE Info: Not Present
        00.. .... = RFU: 0
        Length: 0
    [Connection Parameters in: 2]
    CRC: 0x9a0a11

Frame 1071: Packet, 26 bytes on wire (208 bits), 26 bytes captured (208 bits) on interface COM10-4.6, id 0
nRF Sniffer for Bluetooth LE
    Board: 10
    Header Version: 3, Packet counter: 43385
    Length of packet: 10
    Flags: 0x1b
        .... ...1 = CRC: Ok
        .... ..1. = Direction: Central -> Peripheral
        .... .0.. = Encrypted: No
        .... 1... = MIC (not relevant): 1
        .001 .... = PHY: LE 2M (1)
        0... .... = Reserved: 0
    Channel Index: 25
    RSSI: -57 dBm
    Event counter: 572
    Timestamp: 2866169680µs
    [Packet time (start to end): 44µs]
    [Delta time (end to start): 29763µs]
    [Delta time (start to start): 29807µs]
Bluetooth Low Energy Link Layer
    Access Address: 0x78c6e73a
    [Central Address: QuectelWirel_08:68:dc (24:19:72:08:68:dc)]
    [Peripheral Address: MaximIntegra_ff:9e:b1 (00:18:80:ff:9e:b1)]
    Data Header
        .... ..01 = LLID: Continuation fragment of an L2CAP message, or an Empty PDU (0x1)
        .... .1.. = Next Expected Sequence Number: 1 [ACK]
        .... 1... = Sequence Number: 1 [OK]
        ...0 .... = More Data: False
        ..0. .... = CTE Info: Not Present
        00.. .... = RFU: 0
        Length: 0
    [Connection Parameters in: 2]
    CRC: 0xffba11

Frame 1072: Packet, 26 bytes on wire (208 bits), 26 bytes captured (208 bits) on interface COM10-4.6, id 0
nRF Sniffer for Bluetooth LE
    Board: 10
    Header Version: 3, Packet counter: 43386
    Length of packet: 10
    Flags: 0x1b
        .... ...1 = CRC: Ok
        .... ..1. = Direction: Central -> Peripheral
        .... .0.. = Encrypted: No
        .... 1... = MIC (not relevant): 1
        .001 .... = PHY: LE 2M (1)
        0... .... = Reserved: 0
    Channel Index: 8
    RSSI: -47 dBm
    Event counter: 573
    Timestamp: 2866199681µs
    [Packet time (start to end): 44µs]
    [Delta time (end to start): 29957µs]
    [Delta time (start to start): 30001µs]
Bluetooth Low Energy Link Layer
    Access Address: 0x78c6e73a
    [Central Address: QuectelWirel_08:68:dc (24:19:72:08:68:dc)]
    [Peripheral Address: MaximIntegra_ff:9e:b1 (00:18:80:ff:9e:b1)]
    Data Header
        .... ..01 = LLID: Continuation fragment of an L2CAP message, or an Empty PDU (0x1)
        .... .1.. = Next Expected Sequence Number: 1 [ACK]
        .... 1... = Sequence Number: 1 [Retransmit]
        ...1 .... = More Data: True
        ..0. .... = CTE Info: Not Present
        00.. .... = RFU: 0
        Length: 0
    [Connection Parameters in: 2]
    CRC: 0xcd6211

Frame 1073: Packet, 26 bytes on wire (208 bits), 26 bytes captured (208 bits) on interface COM10-4.6, id 0
nRF Sniffer for Bluetooth LE
    Board: 10
    Header Version: 3, Packet counter: 43387
    Length of packet: 10
    Flags: 0x1b
        .... ...1 = CRC: Ok
        .... ..1. = Direction: Central -> Peripheral
        .... .0.. = Encrypted: No
        .... 1... = MIC (not relevant): 1
        .001 .... = PHY: LE 2M (1)
        0... .... = Reserved: 0
    Channel Index: 27
    RSSI: -58 dBm
    Event counter: 574
    Timestamp: 2866229682µs
    [Packet time (start to end): 44µs]
    [Delta time (end to start): 29957µs]
    [Delta time (start to start): 30001µs]
Bluetooth Low Energy Link Layer
    Access Address: 0x78c6e73a
    [Central Address: QuectelWirel_08:68:dc (24:19:72:08:68:dc)]
    [Peripheral Address: MaximIntegra_ff:9e:b1 (00:18:80:ff:9e:b1)]
    Data Header
        .... ..01 = LLID: Continuation fragment of an L2CAP message, or an Empty PDU (0x1)
        .... .1.. = Next Expected Sequence Number: 1 [ACK]
        .... 1... = Sequence Number: 1 [Retransmit]
        ...1 .... = More Data: True
        ..0. .... = CTE Info: Not Present
        00.. .... = RFU: 0
        Length: 0
    [Connection Parameters in: 2]
    CRC: 0xcd6211

Frame 1074: Packet, 26 bytes on wire (208 bits), 26 bytes captured (208 bits) on interface COM10-4.6, id 0
nRF Sniffer for Bluetooth LE
    Board: 10
    Header Version: 3, Packet counter: 43388
    Length of packet: 10
    Flags: 0x1b
        .... ...1 = CRC: Ok
        .... ..1. = Direction: Central -> Peripheral
        .... .0.. = Encrypted: No
        .... 1... = MIC (not relevant): 1
        .001 .... = PHY: LE 2M (1)
        0... .... = Reserved: 0
    Channel Index: 15
    RSSI: -51 dBm
    Event counter: 575
    Timestamp: 2866259683µs
    [Packet time (start to end): 44µs]
    [Delta time (end to start): 29957µs]
    [Delta time (start to start): 30001µs]
Bluetooth Low Energy Link Layer
    Access Address: 0x78c6e73a
    [Central Address: QuectelWirel_08:68:dc (24:19:72:08:68:dc)]
    [Peripheral Address: MaximIntegra_ff:9e:b1 (00:18:80:ff:9e:b1)]
    Data Header
        .... ..01 = LLID: Continuation fragment of an L2CAP message, or an Empty PDU (0x1)
        .... .1.. = Next Expected Sequence Number: 1 [ACK]
        .... 1... = Sequence Number: 1 [Retransmit]
        ...1 .... = More Data: True
        ..0. .... = CTE Info: Not Present
        00.. .... = RFU: 0
        Length: 0
    [Connection Parameters in: 2]
    CRC: 0xcd6211

Frame 1075: Packet, 26 bytes on wire (208 bits), 26 bytes captured (208 bits) on interface COM10-4.6, id 0
nRF Sniffer for Bluetooth LE
    Board: 10
    Header Version: 3, Packet counter: 43389
    Length of packet: 10
    Flags: 0x1b
        .... ...1 = CRC: Ok
        .... ..1. = Direction: Central -> Peripheral
        .... .0.. = Encrypted: No
        .... 1... = MIC (not relevant): 1
        .001 .... = PHY: LE 2M (1)
        0... .... = Reserved: 0
    Channel Index: 21
    RSSI: -54 dBm
    Event counter: 576
    Timestamp: 2866289684µs
    [Packet time (start to end): 44µs]
    [Delta time (end to start): 29957µs]
    [Delta time (start to start): 30001µs]
Bluetooth Low Energy Link Layer
    Access Address: 0x78c6e73a
    [Central Address: QuectelWirel_08:68:dc (24:19:72:08:68:dc)]
    [Peripheral Address: MaximIntegra_ff:9e:b1 (00:18:80:ff:9e:b1)]
    Data Header
        .... ..01 = LLID: Continuation fragment of an L2CAP message, or an Empty PDU (0x1)
        .... .1.. = Next Expected Sequence Number: 1 [ACK]
        .... 1... = Sequence Number: 1 [Retransmit]
        ...1 .... = More Data: True
        ..0. .... = CTE Info: Not Present
        00.. .... = RFU: 0
        Length: 0
    [Connection Parameters in: 2]
    CRC: 0xcd6211

Frame 1076: Packet, 26 bytes on wire (208 bits), 26 bytes captured (208 bits) on interface COM10-4.6, id 0
nRF Sniffer for Bluetooth LE
    Board: 10
    Header Version: 3, Packet counter: 43390
    Length of packet: 10
    Flags: 0x1b
        .... ...1 = CRC: Ok
        .... ..1. = Direction: Central -> Peripheral
        .... .0.. = Encrypted: No
        .... 1... = MIC (not relevant): 1
        .001 .... = PHY: LE 2M (1)
        0... .... = Reserved: 0
    Channel Index: 27
    RSSI: -57 dBm
    Event counter: 577
    Timestamp: 2866319685µs
    [Packet time (start to end): 44µs]
    [Delta time (end to start): 29957µs]
    [Delta time (start to start): 30001µs]
Bluetooth Low Energy Link Layer
    Access Address: 0x78c6e73a
    [Central Address: QuectelWirel_08:68:dc (24:19:72:08:68:dc)]
    [Peripheral Address: MaximIntegra_ff:9e:b1 (00:18:80:ff:9e:b1)]
    Data Header
        .... ..01 = LLID: Continuation fragment of an L2CAP message, or an Empty PDU (0x1)
        .... .1.. = Next Expected Sequence Number: 1 [ACK]
        .... 1... = Sequence Number: 1 [Retransmit]
        ...1 .... = More Data: True
        ..0. .... = CTE Info: Not Present
        00.. .... = RFU: 0
        Length: 0
    [Connection Parameters in: 2]
    CRC: 0xcd6211

Frame 1077: Packet, 26 bytes on wire (208 bits), 26 bytes captured (208 bits) on interface COM10-4.6, id 0
nRF Sniffer for Bluetooth LE
    Board: 10
    Header Version: 3, Packet counter: 43391
    Length of packet: 10
    Flags: 0x1b
        .... ...1 = CRC: Ok
        .... ..1. = Direction: Central -> Peripheral
        .... .0.. = Encrypted: No
        .... 1... = MIC (not relevant): 1
        .001 .... = PHY: LE 2M (1)
        0... .... = Reserved: 0
    Channel Index: 20
    RSSI: -56 dBm
    Event counter: 578
    Timestamp: 2866349686µs
    [Packet time (start to end): 44µs]
    [Delta time (end to start): 29957µs]
    [Delta time (start to start): 30001µs]
Bluetooth Low Energy Link Layer
    Access Address: 0x78c6e73a
    [Central Address: QuectelWirel_08:68:dc (24:19:72:08:68:dc)]
    [Peripheral Address: MaximIntegra_ff:9e:b1 (00:18:80:ff:9e:b1)]
    Data Header
        .... ..01 = LLID: Continuation fragment of an L2CAP message, or an Empty PDU (0x1)
        .... .1.. = Next Expected Sequence Number: 1 [ACK]
        .... 1... = Sequence Number: 1 [Retransmit]
        ...1 .... = More Data: True
        ..0. .... = CTE Info: Not Present
        00.. .... = RFU: 0
        Length: 0
    [Connection Parameters in: 2]
    CRC: 0xcd6211

Frame 1078: Packet, 26 bytes on wire (208 bits), 26 bytes captured (208 bits) on interface COM10-4.6, id 0
nRF Sniffer for Bluetooth LE
    Board: 10
    Header Version: 3, Packet counter: 43392
    Length of packet: 10
    Flags: 0x1b
        .... ...1 = CRC: Ok
        .... ..1. = Direction: Central -> Peripheral
        .... .0.. = Encrypted: No
        .... 1... = MIC (not relevant): 1
        .001 .... = PHY: LE 2M (1)
        0... .... = Reserved: 0
    Channel Index: 33
    RSSI: -57 dBm
    Event counter: 579
    Timestamp: 2866379687µs
    [Packet time (start to end): 44µs]
    [Delta time (end to start): 29957µs]
    [Delta time (start to start): 30001µs]
Bluetooth Low Energy Link Layer
    Access Address: 0x78c6e73a
    [Central Address: QuectelWirel_08:68:dc (24:19:72:08:68:dc)]
    [Peripheral Address: MaximIntegra_ff:9e:b1 (00:18:80:ff:9e:b1)]
    Data Header
        .... ..01 = LLID: Continuation fragment of an L2CAP message, or an Empty PDU (0x1)
        .... .1.. = Next Expected Sequence Number: 1 [ACK]
        .... 1... = Sequence Number: 1 [Retransmit]
        ...1 .... = More Data: True
        ..0. .... = CTE Info: Not Present
        00.. .... = RFU: 0
        Length: 0
    [Connection Parameters in: 2]
    CRC: 0xcd6211

Frame 1079: Packet, 26 bytes on wire (208 bits), 26 bytes captured (208 bits) on interface COM10-4.6, id 0
nRF Sniffer for Bluetooth LE
    Board: 10
    Header Version: 3, Packet counter: 43393
    Length of packet: 10
    Flags: 0x1b
        .... ...1 = CRC: Ok
        .... ..1. = Direction: Central -> Peripheral
        .... .0.. = Encrypted: No
        .... 1... = MIC (not relevant): 1
        .001 .... = PHY: LE 2M (1)
        0... .... = Reserved: 0
    Channel Index: 35
    RSSI: -55 dBm
    Event counter: 580
    Timestamp: 2866409688µs
    [Packet time (start to end): 44µs]
    [Delta time (end to start): 29957µs]
    [Delta time (start to start): 30001µs]
Bluetooth Low Energy Link Layer
    Access Address: 0x78c6e73a
    [Central Address: QuectelWirel_08:68:dc (24:19:72:08:68:dc)]
    [Peripheral Address: MaximIntegra_ff:9e:b1 (00:18:80:ff:9e:b1)]
    Data Header
        .... ..01 = LLID: Continuation fragment of an L2CAP message, or an Empty PDU (0x1)
        .... .1.. = Next Expected Sequence Number: 1 [ACK]
        .... 1... = Sequence Number: 1 [Retransmit]
        ...1 .... = More Data: True
        ..0. .... = CTE Info: Not Present
        00.. .... = RFU: 0
        Length: 0
    [Connection Parameters in: 2]
    CRC: 0xcd6211

Frame 1080: Packet, 26 bytes on wire (208 bits), 26 bytes captured (208 bits) on interface COM10-4.6, id 0
nRF Sniffer for Bluetooth LE
    Board: 10
    Header Version: 3, Packet counter: 43394
    Length of packet: 10
    Flags: 0x1b
        .... ...1 = CRC: Ok
        .... ..1. = Direction: Central -> Peripheral
        .... .0.. = Encrypted: No
        .... 1... = MIC (not relevant): 1
        .001 .... = PHY: LE 2M (1)
        0... .... = Reserved: 0
    Channel Index: 25
    RSSI: -56 dBm
    Event counter: 581
    Timestamp: 2866439689µs
    [Packet time (start to end): 44µs]
    [Delta time (end to start): 29957µs]
    [Delta time (start to start): 30001µs]
Bluetooth Low Energy Link Layer
    Access Address: 0x78c6e73a
    [Central Address: QuectelWirel_08:68:dc (24:19:72:08:68:dc)]
    [Peripheral Address: MaximIntegra_ff:9e:b1 (00:18:80:ff:9e:b1)]
    Data Header
        .... ..01 = LLID: Continuation fragment of an L2CAP message, or an Empty PDU (0x1)
        .... .1.. = Next Expected Sequence Number: 1 [ACK]
        .... 1... = Sequence Number: 1 [Retransmit]
        ...1 .... = More Data: True
        ..0. .... = CTE Info: Not Present
        00.. .... = RFU: 0
        Length: 0
    [Connection Parameters in: 2]
    CRC: 0xcd6211

[khpeterson]

For what it's worth, I also added logging in lctrSlvConnTxCompletion and though I don't have a Wireshark capture for this run, the sequence is identical and it's clear that no errors are returned by the BB tx path.

Here's the extra logging:

diff --git a/Libraries/Cordio/controller/sources/ble/lctr/lctr_isr_conn_slave.c b/Libraries/Cordio/controller/sources/ble/lctr/lctr_isr_conn_slave.c
index 86988752b9..768a0bd715 100644
--- a/Libraries/Cordio/controller/sources/ble/lctr/lctr_isr_conn_slave.c
+++ b/Libraries/Cordio/controller/sources/ble/lctr/lctr_isr_conn_slave.c
@@ -638,9 +638,16 @@ void lctrSlvConnTxCompletion(BbOpDesc_t *pOp, uint8_t status)
   if (status == BB_STATUS_SUCCESS)
   {
     lctrConnCtx_t * const pCtx = pOp->pCtx;
-
+    LL_TRACE_INFO2("lctrSlvConnTxCompletion: status=BB_STATUS_SUCCESS, handle=%u, eventCounter=%u",
+                   LCTR_GET_CONN_HANDLE(pCtx), pCtx->eventCounter);
     lctrSetControlPduAck(pCtx);
   }
+  else
+  {
+    lctrConnCtx_t * const pCtx = pOp->pCtx;
+    LL_TRACE_WARN3("lctrSlvConnTxCompletion: BB failed with status=%u, handle=%u, eventCounter=%u",
+                   status, LCTR_GET_CONN_HANDLE(pCtx), pCtx->eventCounter);
+  }
 }

And here's what the console shows at the time of the PHY update with txPhy=1 and and rxPhy=2:

lctrSlvLlcpExecutePhyUpdateSm: handle=0, llcpState=IDLE, phyUpdState=0, event=2
>>> Data Path Tx Paused, handle=0 <<<
lctrSlvConnTxCompletion: status=BB_STATUS_SUCCESS, handle=0, eventCounter=246
lctrSlvLlcpExecutePhyUpdateSm: handle=0, llcpState=BUSY, phyUpdState=3, event=6
>>> Data Path Tx Unpaused/Resumed, handle=0 <<<
lctrSlvConnTxCompletion: status=BB_STATUS_SUCCESS, handle=0, eventCounter=247
lctrSlvLlcpExecutePhyUpdateSm: handle=0, llcpState=BUSY, phyUpdState=4, event=1
lctrSlvConnTxCompletion: status=BB_STATUS_SUCCESS, handle=0, eventCounter=248
lctrSlvConnTxCompletion: status=BB_STATUS_SUCCESS, handle=0, eventCounter=249
lctrSlvConnTxCompletion: status=BB_STATUS_SUCCESS, handle=0, eventCounter=250
lctrProcessRxAck: RETRANSMIT, handle=0, sn=0, nesn=189
lctrSlvConnTxCompletion: status=BB_STATUS_SUCCESS, handle=0, eventCounter=251
lctrSlvConnRxCompletion: BB failed with status=CRC_FAILED, handle=0, bleChan=29, eventCounter=252
lctrProcessRxAck: RETRANSMIT, handle=0, sn=0, nesn=189
lctrSlvConnTxCompletion: status=BB_STATUS_SUCCESS, handle=0, eventCounter=253
lctrSlvConnRxCompletion: BB failed with status=CRC_FAILED, handle=0, bleChan=2, eventCounter=254
lctrSlvConnRxCompletion: BB failed with status=CRC_FAILED, handle=0, bleChan=20, eventCounter=255
lctrProcessRxAck: RETRANSMIT, handle=0, sn=0, nesn=189
lctrSlvConnTxCompletion: status=BB_STATUS_SUCCESS, handle=0, eventCounter=256
>>> PHY updated, handle=0, eventCounter=257 <<<
txPhy=1, rxPhy=2
lctrSlvConnRxCompletion: BB failed with status=RX_TIMEOUT, handle=0, bleChan=0, eventCounter=257
lctrSlvLlcpExecutePhyUpdateSm: handle=0, llcpState=BUSY, phyUpdState=5, event=4
### LlEvent ###  LL_PHY_UPDATE_IND, phy=1, handle=0, status=0
Ble got evt 70
DM_PHY_UPDATE_IND - RX: 2, TX: 1
lctrSlvConnTxCompletion: status=BB_STATUS_SUCCESS, handle=0, eventCounter=258
lctrSlvConnRxCompletion: BB failed with status=RX_TIMEOUT, handle=0, bleChan=10, eventCounter=258
lctrProcessRxAck: RETRANSMIT, handle=0, sn=1, nesn=190
lctrSlvConnTxCompletion: status=BB_STATUS_SUCCESS, handle=0, eventCounter=259
lctrSlvConnRxCompletion: BB failed with status=RX_TIMEOUT, handle=0, bleChan=12, eventCounter=259
hciCoreTxAclStart len=177
Ble got evt 18
lctrSlvConnRxCompletion: BB failed with status=CRC_FAILED, handle=0, bleChan=7, eventCounter=260
lctrProcessRxAck: RETRANSMIT, handle=0, sn=1, nesn=190
lctrSlvConnTxCompletion: status=BB_STATUS_SUCCESS, handle=0, eventCounter=261
lctrSlvConnRxCompletion: BB failed with status=RX_TIMEOUT, handle=0, bleChan=30, eventCounter=261
lctrProcessRxAck: RETRANSMIT, handle=0, sn=1, nesn=190
lctrSlvConnTxCompletion: status=BB_STATUS_SUCCESS, handle=0, eventCounter=262
lctrSlvConnRxCompletion: BB failed with status=RX_TIMEOUT, handle=0, bleChan=30, eventCounter=262
lctrProcessRxAck: RETRANSMIT, handle=0, sn=1, nesn=190
lctrSlvConnTxCompletion: status=BB_STATUS_SUCCESS, handle=0, eventCounter=263
lctrSlvConnRxCompletion: BB failed with status=RX_TIMEOUT, handle=0, bleChan=23, eventCounter=263
lctrProcessRxAck: RETRANSMIT, handle=0, sn=1, nesn=190
lctrSlvConnTxCompletion: status=BB_STATUS_SUCCESS, handle=0, eventCounter=264
lctrSlvConnRxCompletion: BB failed with status=RX_TIMEOUT, handle=0, bleChan=20, eventCounter=264
lctrProcessRxAck: RETRANSMIT, handle=0, sn=1, nesn=190
lctrSlvConnTxCompletion: status=BB_STATUS_SUCCESS, handle=0, eventCounter=265
lctrSlvConnRxCompletion: BB failed with status=RX_TIMEOUT, handle=0, bleChan=12, eventCounter=265
lctrProcessRxAck: RETRANSMIT, handle=0, sn=1, nesn=190
lctrSlvConnTxCompletion: status=BB_STATUS_SUCCESS, handle=0, eventCounter=266
lctrSlvConnRxCompletion: BB failed with status=RX_TIMEOUT, handle=0, bleChan=2, eventCounter=266
lctrProcessRxAck: RETRANSMIT, handle=0, sn=1, nesn=190
lctrSlvConnTxCompletion: status=BB_STATUS_SUCCESS, handle=0, eventCounter=267
lctrSlvConnRxCompletion: BB failed with status=RX_TIMEOUT, handle=0, bleChan=26, eventCounter=267
lctrProcessRxAck: RETRANSMIT, handle=0, sn=1, nesn=190
lctrSlvConnTxCompletion: status=BB_STATUS_SUCCESS, handle=0, eventCounter=268
lctrSlvConnRxCompletion: BB failed with status=RX_TIMEOUT, handle=0, bleChan=2, eventCounter=268
lctrProcessRxAck: RETRANSMIT, handle=0, sn=1, nesn=190
lctrSlvConnTxCompletion: status=BB_STATUS_SUCCESS, handle=0, eventCounter=269
lctrSlvConnRxCompletion: BB failed with status=RX_TIMEOUT, handle=0, bleChan=34, eventCounter=269
lctrSlvConnRxCompletion: BB failed with status=RX_TIMEOUT, handle=0, bleChan=10, eventCounter=270
lctrProcessRxAck: RETRANSMIT, handle=0, sn=1, nesn=190
lctrSlvConnTxCompletion: status=BB_STATUS_SUCCESS, handle=0, eventCounter=271
lctrSlvConnRxCompletion: BB failed with status=RX_TIMEOUT, handle=0, bleChan=5, eventCounter=271
lctrProcessRxAck: RETRANSMIT, handle=0, sn=1, nesn=190
lctrSlvConnTxCompletion: status=BB_STATUS_SUCCESS, handle=0, eventCounter=272
lctrSlvConnRxCompletion: BB failed with status=RX_TIMEOUT, handle=0, bleChan=35, eventCounter=272
lctrProcessRxAck: RETRANSMIT, handle=0, sn=1, nesn=190
lctrSlvConnTxCompletion: status=BB_STATUS_SUCCESS, handle=0, eventCounter=273
lctrSlvConnRxCompletion: BB failed with status=RX_TIMEOUT, handle=0, bleChan=4, eventCounter=273
lctrProcessRxAck: RETRANSMIT, handle=0, sn=1, nesn=190
lctrSlvConnTxCompletion: status=BB_STATUS_SUCCESS, handle=0, eventCounter=274
lctrSlvConnRxCompletion: BB failed with status=RX_TIMEOUT, handle=0, bleChan=16, eventCounter=274
lctrProcessRxAck: RETRANSMIT, handle=0, sn=1, nesn=190
lctrSlvConnTxCompletion: status=BB_STATUS_SUCCESS, handle=0, eventCounter=275
lctrSlvConnRxCompletion: BB failed with status=RX_TIMEOUT, handle=0, bleChan=4, eventCounter=275
lctrProcessRxAck: RETRANSMIT, handle=0, sn=1, nesn=190
lctrSlvConnTxCompletion: status=BB_STATUS_SUCCESS, handle=0, eventCounter=276
lctrSlvConnRxCompletion: BB failed with status=RX_TIMEOUT, handle=0, bleChan=22, eventCounter=276
lctrProcessRxAck: RETRANSMIT, handle=0, sn=1, nesn=190
lctrSlvConnTxCompletion: status=BB_STATUS_SUCCESS, handle=0, eventCounter=277
lctrSlvConnRxCompletion: BB failed with status=RX_TIMEOUT, handle=0, bleChan=0, eventCounter=277
01006000: tick
lctrProcessRxAck: RETRANSMIT, handle=0, sn=1, nesn=190
lctrSlvConnTxCompletion: status=BB_STATUS_SUCCESS, handle=0, eventCounter=278
lctrSlvConnRxCompletion: BB failed with status=RX_TIMEOUT, handle=0, bleChan=35, eventCounter=278
lctrProcessRxAck: RETRANSMIT, handle=0, sn=1, nesn=190
lctrSlvConnTxCompletion: status=BB_STATUS_SUCCESS, handle=0, eventCounter=279
lctrSlvConnRxCompletion: BB failed with status=RX_TIMEOUT, handle=0, bleChan=20, eventCounter=279
lctrProcessRxAck: RETRANSMIT, handle=0, sn=1, nesn=190
lctrSlvConnTxCompletion: status=BB_STATUS_SUCCESS, handle=0, eventCounter=280
lctrSlvConnRxCompletion: BB failed with status=RX_TIMEOUT, handle=0, bleChan=36, eventCounter=280