Prescheduled classes missing or messed up!

It was the second time when I have done prescheduling weekly meetings and reoccurrences, say for 10 weeks. I checked and saved, then sporadically, the class was missing from the schedule. When I logged in this morning and couldn't find the meeting, I had 10 minutes to send another invitation to the participants. Some couldn't get in using the last week link and some noticed that a new link was sent. As a result, only half of the participants were in the meeting.

How could I avoid it? What could the Zoom team do to fix it? 

Thanks!