Backup job failed after days but won't restart

If you have logs left (e.g. if it was a different backup), please look at RetryAttempts value as requested.
Anything over the Internet is a bit unstable, and if you’re on a public storage, they also occasionally fail.

Any clues given? Perhaps you deleted the job log (and there may have been no log), but see server log.

The backup history in UTC looks like the below. Maybe the stop was on first one, and the restart ran for days then reported the error message you cite at end of backup, and the next two reported at the start?

Backup	Monday, November 16, 2020 3:09:14 PM
Backup	Tuesday, November 17, 2020 6:24:31 PM
Backup	Friday, November 20, 2020 11:43:41 AM
Backup	Friday, November 20, 2020 11:44:47 AM

Can you confirm or amend? I think the same consistency check runs before and after a backup. Seeing consistency failures hang around and break future starts is normal, unless the issue is fixed in between. Seeing a backup pass its before-start check and fail later in the same run is worrisome if that happened.

Look both for a job log and the server log, however neither is as good a record as setting up a debug log.
Advanced options log-file=<path> at log-file-log-level=retry might be a good plan (there are higher levels).