FilePicker does not accept keystrokes after Ctrl+S

[shinta0806]

Describe the bug

FilePicker does not accept keystrokes when opened in KeyboardAccelerators.
(Occasionally accepts keystrokes. Once accepted, it will be accepted thereafter.)

If the FilePicker is opened by clicking on the menu with the mouse, the FilePicker accepts keystrokes.

Steps to reproduce the bug

1. Assign KeyboardAccelerators (Ctrl+S) to the Save menu
2. Ctrl+S
3. Open FileSavePicker
4. FileSavePicker does not accept keystrokes

Sample program in GitHub:
https://github.com/shinta0806/TestFilePicker

Expected behavior

No response

Screenshots

NuGet package version

WinUI 3 - Windows App SDK 1.5.0: 1.5.240227000

Windows version

Windows 11 (22H2): Build 22621

Additional context

No response