Waiting room not working

We are using a Pro account to host a seminar series, and the waiting room is not working at all. We activated it in the Settings, choosing "everyone will go in the waiting room."  When the core group of us met this morning, it did not work at all. I am testing it further this afternoon by checking the settings and starting a meeting, then joining the meeting via mobile from a different account. Still, no waiting room function.

We have 60+ paid participants joining a seminar series that starts tomorrow, and we really want this function to be in place.