I'm submitting this in the hope that it gets fixed even though I suspect that it may be the result of the macOS 12.3.1 update. It actually started happening well before rc8 was released. Last successful backup was on April 30th. Now I can create a new share for time machine backups and the first backup will be successful. Subsequent backups will fail with an error in time machine "Failed to attach using DiskImages2".
Time Machine log-
2022-05-11 22:03:04 Cleared pending cancellat
Solved
Yeah, this could definitely be the case. I agree completely that Apple could be going off the rails in how things are built. But considering upgrading the server causes the breakage while the Apple device stays the same, and the Time Machine functionality in Unraid is built exclusively for Apple devices, I would have hoped that Limetech could have pinned the Samba version on something functional (or at least tested it in 6.10 to a thorough degree).
It's not a good look for Limetech