Antivirus does not load with multiple users

I have a notebook where we run multiple businesses on with divergent users. We have a master account that controls the installs and guest accounts that cannot configure items to protect the rest from the users on the notebook.

Now when the master account loges on all is working well but if one of the guest logs the real-time On Access scanning of the scanner does not start. When shutting down the whole scanner and start it up again all works well?