Unhandled exception when closing window after expanding the SelectionFlyout of RichEditBox

[nynauy]

Describe the bug

An unhandled exception occurs when closing a window containing a RichEditBox with its SelectionFlyout expanded.

Steps to reproduce the bug

1. Create a blank WinUI 3 app.
2. Place only one RichEditBox control in the MainWindow.
3. Build and run the app.
4. Type something in the RichEditBox.
5. Select some text to make the flyout appear.
6. Click [...] to expand the flyout.
7. Immediately click the window's close button.

Expected behavior

The app exits without unhandled exceptions.

Screenshots

Reproduce.mp4

NuGet package version

WinUI 3 - Windows App SDK 1.7.0: 1.7.250310001

Windows version

Windows 11 (24H2): Build 26100

Additional context

No response