Need to hide PDFs for users not logges in

I'm using URL groups and add it as a negative rule for unregistered. When I use /?s= it works.

The problem is a automatic PDF creation based on the plugin mpdf. I added*
/?print=pdf to the URL group but it is possible to view the PDF even if not logged in...

Any tips on this? I know I asked before but I can't find the answer on that.

Do you need more info? I'll do a PM with URLs because it's sensitive info...