Parametric dispersion fit failed

[Cem-Gulec]

Describe the bug

To Reproduce
covid:
"EFO:0011025_UBERON:0000178_CL:0000897" "10x 5' v1_blood_CD4-positive, alpha-beta memory T cell"
Assay: 10x 5' v1 (EFO:0011025), Tissue: blood (UBERON:0000178), Cell Type: immature B cell (CL:0000816)
Assay: 10x 5' v1 (EFO:0011025), Tissue: blood (UBERON:0000178), Cell Type: neutrophil (CL:0000775)

gtex:
"EFO:0009899_UBERON:0001388_CL:0000235" "10x 3' v2_gastrocnemius_macrophage"
Assay: 10x 3' v2 (EFO:0009899), Tissue: skin of leg (UBERON:0001511), Cell Type: endothelial cell of lymphatic vessel (CL:0002138)
Assay: 10x 3' v2 (EFO:0009899), Tissue: skin of leg (UBERON:0001511), Cell Type: professional antigen presenting cell (CL:0000145)
Assay: 10x 3' v2 (EFO:0009899), Tissue: skin of leg (UBERON:0001511), Cell Type: T cell (CL:0000084)

immune - Global dataset:
"EFO:0011025_UBERON:0002509_CL:0000990" "10x 5' v1_mesenteric lymph node_conventional dendritic cell"
Assay: 10x 5' v1 (EFO:0011025), Tissue: mesenteric lymph node (UBERON:0002509), Cell Type: macrophage (CL:0000235)
Assay: 10x 5' v1 (EFO:0011025), Tissue: mesenteric lymph node (UBERON:0002509), Cell Type: alpha-beta T cell (CL:0000789)
Assay: 10x 5' v1 (EFO:0011025), Tissue: spleen (UBERON:0002106), Cell Type: alpha-beta T cell (CL:0000789)

skeletal muscle - All Cells:
"EFO:0009922_UBERON:0010033_CL:0002144" "10x 3' v3_posterior part of tongue_capillary endothelial cell"
Assay: 10x 3' v3 (EFO:0009922), Tissue: eye (UBERON:0000970), Cell Type: melanocyte (CL:0000148)
Assay: 10x 3' v3 (EFO:0009922), Tissue: cardiac atrium (UBERON:0002081), Cell Type: smooth muscle cell (CL:0000192)
Assay: 10x 3' v3 (EFO:0009922), Tissue: cardiac ventricle (UBERON:0002082), Cell Type: smooth muscle cell (CL:0000192)

pancreas - Human pancreatic islet cells:
"EFO:0009899_UBERON:0000006_CL:0002275" "10x 3' v2_islet of Langerhans_pancreatic PP cell"