Preventing attendees from starting meeting before organiser

PositiveEnergy This is not the issue.  I already have my lobby set up like that.  I (and I think several others) are talking about the fact that students can start meetings and sit in the lobby for hours.  Most of the time when I join a meeting I have a similar message to the one attached. For those who are not educators and can't figure out why this is a problem, students are very good at getting around doing things they should be doing.  If they start all of their meetings in the morning, they can walk away from their computer and be "in" class without actually attending.  I know this is happening because sometimes, I end the meeting and restart it myself and not all of them come back.  I've also left meetings going after class time and have "students" sitting there well into their next class.  I know there is a setting at the district level but clearly our district doesn't feel it is important enough to change.