petri[.]com/how-to-reset-onedrive-synchronization/
The article advises restarting OneDrive, or trying to pause, then resume syncing, and covers some stuff like using illegal file names that just won't work. If none of that works, it tells you how to perform a reset.
Alright, well, if you’ve tried all the steps above and you’re still stuck, the last resort is to reset OneDrive. Here are the steps you need to follow:Open a Run dialog window by pressing the Windows key + R.
Copy and paste this text into the window, and press OK – %localappdata%\Microsoft\OneDrive\onedrive.exe /reset
If you see a ‘Windows cannot find…’ message, copy and paste THIS text instead and press OK: – C:\Program Files\Microsoft OneDrive\onedrive.exe /reset
If that ALSO doesn’t work, you can try this text and press OK: – C:\Program Files (x86)\Microsoft OneDrive\onedrive.exe /reset
Then, manually restart OneDrive by clicking the Start button, typing in OneDrive, and clicking the OneDrive (desktop) app. You may need to log in again from scratch with your Microsoft Account or Office 365 (work or school) account.