Several users and administrators who want to upgrade Apple computers to macOS Big Sur 11.1 have encountered problems. It appears to be a simple bug in Mobile Device Management.
Users briefly receive a notification that an update to version 11.1 is ready. Unfortunately, this message disappears quickly before the user has been able to take action. Ars Technica also writes that updating via the softwareupdate command in the Terminal doesn’t work either.
Version 11.0.1
Developer Victor Vrantchan thinks he has found the cause of the problem: some computers request version 11.0.1 from the update server instead of version 11.1. In most cases, version 11.0.1 is already installed on the computer, which causes the problems.
Workaround
In some restarting the affected computers helps, but most of the time it only briefly displays the update notification before it disappears again. A possible workaround is to remove the Mobile Device Management profile, but this might cause other problems.
Patching might be tricky
Since the bug prevents the operating system from being updated, it could be difficult for Apple to patch it. If it cannot be fixed with a new update, a user could fall back to completely reinstalling macOS 11.1 on their computers.