Hi,
Did the user try to re-set OneDrive for Mac?
I suggest you refer to this support article about resetting OneDrive:
You can try this method first, if this issue is still existed, try to reinstall OneDrive for Mac:
Just checking in to see if the information was helpful. Please let us know if you would like further assistance.
If the response is helpful, please click "Accept Answer" and upvote it.
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.