Entrei em contato com o thefanclub e Christiaan Diedericks gentilmente respondeu com uma solução que realmente funciona! É o seguinte:
Make sure you use the latest version 3.2.3 from our website : https://www.thefanclub.co.za/overgrive
Clear all trashed files from your Google Drive online Trash/Bin folder.
Delete the following files from your local Google Drive folder restart the program.
- .overgrive.cache
- .overgrive.auth
You will find the setup screen again. Do the setup and click "Start Sync"
It does not download all the files again. It just "checks" every file and rebuilds the local cache file. It takes time, but no files will be downloaded if they exist already.
You have to wait for the sync to complete before making any changes.