Active Directory does not work propperly

[Mabelines]

We are working on integrating dokuwiki in our company and also checked out the notification plugin. I noticed that the option user: $USER$ does not work when you use the Active Directory Plugin for authentication.
If you specify the user manually all the notification for this user get displayed, but if you use the variable it just displays no notifications.
Am I missing something or was this never a problem before?

Maybe I can provide some information to solve this issue.