Participants getting kicked out during 1-2 hour webinars

During a 1-2 hour webinar, I have multiple attendees who will get kicked off the zoom webinar and will be unable to rejoin. What is causing so many people to get kicked off? Usually, we have anywhere between 200-700 people that attend our weekly webinars, and anywhere between 10-40 will get kicked out during the duration of the webinar.