Microsoft has confirmed a unique bug in a stable version of Windows 11 that may prevent users from signing in after adding a new Microsoft account. Microsoft says users get locked out briefly after the first restart or sign-out.
The problem only appears once and only appears on systems running Windows 11 21H2. Those using Azure or Active Directory services are not impacted. Users experiencing the problems on 21H2 shouldn't do anything to fix the problem, the system will allow them to sign back in within a few minutes. Microsoft did resolve the issue using the Known Issue Rollback System which automatically resolves issues without any user input.