• WDD Version: 5.6.0.0
• OS Version: Windows 11

Steps to Reproduce:

1. Deploy latest OS on X64 Machine.
2. Perform Windows and Store updates.
3. Install the application from Microsoft store.
4. Launch the application.
5. Select lockscreen from the dropdown in the top left corner.
6. Select any downloaded theme and click on apply.
7. Observe unable to apply selected theme.

Are you using the Microsoft Store version of WDD?: Yes