Windows 10 OneDrive folder assigned to wrong folder - how to fix

Hi

I'm servicing a laptop running windows 10.  In the Explorer, the wrong folder has been assigned as the OndDrive folder, and it's causing problems.  The OneDrive folder has apparently been assigned to the Documents folder in the Explorer.  (C:\users\XXXX\OneDrive\Documents).  So when ever I access the documents I receive the "Location is not available" if the Documents folder is not actually being sync'd.  If the Documents folder is being sync'd, it is populated only as far as the OneDrive folder would be.

I've tried changing to a local sign in, and then back to a microsoft login to no avail. I've tried changing the location by going into OneDrive settings.  Still the Documents folder remains the folder assisgned as the OneDrive folder.   Amongst other indicators, the Documents folder has the options to "Choose OneDrive folders to sync" whereas the OneDrive folder does not.

The file system is predictably intact and the c:\users\xxxxx\Documents folder is there and populated.

So how to force the OneDrive folder back to be the OneDrive folder and remove the assignemt from the Documents folder?

Thanks for any insight.

Mark