OneDrive hängt bei der PDF-Synchronisierung auf dem iPad

I have tried everything and do not know what to do...

Problem: I use my iPad to edit files, mainly PDFs. Since yesterday (I think) the syncing does not work anymore. I edit a PDF, click on "safe". The "syncing" bar opens. But it is stuck at 0%, and I have absolutely no idea why.

Tried solutions: My iPad is up to date (and not as old as to be affected by this: https://support.microsoft.com/de-de/office/lifecycle/officeinstall/update-m365-office-macos-ios), so is my OneDrive. OneDrive works normally on Mac and on iPhone. I have restarted my iPad, deinstalled Onedrive (and then restarted), eliminated the cache, logged in and out of my account, tried editing other PDF files (same problem).

Any ideas, what might be wrong? I really have no clue....