A Microsoft file hosting and synchronization service.
I had the same problem on a PC (Win 11) after a major update, in June 24.
Tried everything, the only solution was:
- format and reinstall everything
- delete the old user (delete the micro$oft account!)
- create a new AND DIFFERENT user (with different mail address, of course).
- upload my previous backup on the new OneDrive.
It worked, but yesterday (FEB 25) the issue is back. In the next days I'll wipe again PC and so on.
And today, on another computer (MBPro) with different user, same problem. So I think I'll have some work to do.
It's not a big solution, but it's the best I found.