the only general recommendation I have is to upgrade to the latest 7.2 version, if you are not running it. Several improvements have been made to solve issues like the one you describe. If that does not help a deeper analysis has to be performed. You should file a service request with tech support for this purpose.
We are already running v18.104.22.168.0 and I have raised a call with McAfee, I just wondered if other users were experiencing the same issues.
If affected users use another generic username then all is ok so it does sound like a quota issue to me.
I have previously asked McAfee that question and they said not. Unfortunately I would have to stop the services to delete the db files to test my theory which takes away Internet access.
McAfee have said that this is a known issue with v22.214.171.124.0 and that I should upgrade.