OneDrive (personal) back-ups suddenly started failing with "Channel is retired" and "A task has been cancelled"

What’s wrong with your backup? I see no information anywhere. Have you followed the steps here to see whether you’re getting timeouts? If so, then somebody (perhaps me) can then go off to see how one sets larger timeouts for Azure. One challenge with timeouts is that different destination type may set differently. For example, setting an http timeout on SFTP or FTP wouldn’t make any sense. At least Azure uses http, however (just as AWS does) it has its own application programming interface (which I’m not familiar with).

Release: 2.0.4.6 (canary) 2018-12-11 is already out, and it’s canary. Numbers are not meant to be reused. If you’re just asking if you need to wait for next beta, that’s generally only an option for a fix at all if a canary or experimental (less bleeding edge than canary) has the fix. Not knowing the issue, I can’t say anything…