I haven’t personally had one never come back, but it has sometimes exceeded the retries I chose…
Implement exponential backoff for backend errors #4661 was recently done by a volunteer. Thanks!
Scheduled Backup Failure: Google Drive: (403) Forbidden was cited, and Google suggests backoff.
If you have a fast system and upload, it’s possible your 800 GB helped push past 750 GB daily limit.
That will mean even 20 retries won’t get past it, and you’ll have to wait for Google to unlock things…