I applied some windows maintenance to a Windows 11 system and started getting the message about the clock not being syncronized. After the backup runs for about an hour, you get the message that the clocks are not syncronized. When you check, the system clock is indeed wrong. It seems to have stalled at the time the backup started.

I did apply KB5007262 and KB5007292 right before the problem started.

I removed KB5007262 and the error continued (happened on 3 tries)

I removed KB007292 and the problem (so far) has gone away. Three backups completed successfully. I am running the current version of Server Edition.