It's possible that the issue is caused by a conflicting Group Policy setting. There are some Group Policy settings that take precedence over others, so even if you have set a specific value for a policy, another setting may be overriding it.
To troubleshoot the issue, you can try the following steps:
- Check the Group Policy settings on the Domain Controller. Make sure that the policy for minimum PIN complexity is still enabled and set to 4 digits. You can use the Group Policy Management Console (GPMC) to do this.
- Run the command "gpresult /h report.html" on the affected Windows 11 computer to generate a report of the applied Group Policy settings. Check the report to see if there are any conflicting policies that may be overriding the minimum PIN complexity policy.
- Check the Windows 11 computer's registry to see if there are any conflicting settings there. To do this, open the Registry Editor and navigate to "HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\System". Look for a value named "AllowDomainPINLogon" and make sure it is set to "1". Also, check if there are any other PIN-related policies that may be overriding the minimum PIN complexity policy.
- Try disabling and re-enabling the minimum PIN complexity policy on the Domain Controller. This may help to refresh the policy on the Windows 11 computer.
If none of these steps resolve the issue, it's possible that there may be a bug or compatibility issue with the version of Windows 11 you are using. You may want to check for any available updates or patches that may address the issue, or contact Microsoft support for further assistance.