Windows Authentication via Active Directory fail mode NOT as per documentation

[behennad]

We have configured WinCC OA project to use active diretcory for user authentication.

Documentation advises that on failure of active directory users can still log on to WinCC OA application using last successful login details.

If we fail the Active Directory Server ONLY the root user can log to the server all opther accounts do NOT operate.

If we check the WinCC OA users list all the users that had logged on using AD are visible in the user list.