I use a file sharing app called Dropshare, available via my Setapp subscription. I have it linked to my OneDrive account as it has over 200 GB of available space, much more than I have with iCloud Drive or Google Drive. Today I tried to upload a file via Dropshare, only to be informed that there were no OneDrive tokens available.
I wasn’t sure what that meant so I deleted the OneDrive connection from Dropshare then re-established it. The final stage of that process was signing into OneDrive. Now the connection works properly again.