White Box blocking Acrobat Pro - Windows 11

Hi,

I am an IT engineer supporting users on Acrobat Pro

I have a user at the moment who is getting an issue where a white box appears over the top of their Acrobat Pro window, and never goes away. It has a flickering loading circle on it, which constantly flickers on and off but never does anything else.

I have looked this up as a white box blocking the window seems to be a common problem with Acrobat, but none of the fixes in the other posts about this issue on the forums have worked.

Here is a full list of everything I have tried to fix the issue:

1.  Reinstalled Acrobat by itself
2.  Reinstalled Creative Cloud
3. Logged out of both the Creative Cloud app and the Acrobat app individually, and signed back in
4. Uninstalled both Acrobat and Creative Cloud, then went into the Adobe folders in appdata\local , appdata\roaming and \Program Files and deleted everything, then reinstalled using a newly downloaded installer
5. Removed the user's account from the admin centre, then reinvited them
6. Removed the user's account from the admin centre, then reinvited them via a different email address to force it to generate a new user profile
7. Deleted everything Adobe-related from Windows Credentials Manager
8. Performed an SFC /Scannow and a DISM.EXE repair via command prompt
9. Ran Acrobat Distiller as advised by this post: https://community.adobe.com/t5/acrobat-discussions/an-empty-white-box-is-blocking-my-pdf/m-p/11149770#M258058
10. Disabled 'Show online storage when opening files' from this post https://community.adobe.com/t5/acrobat-discussions/white-box-blocking-the-use-of-adobe-acrobat/m-p/12365633#M327445