My students are unable to join the remote presentation at the same time. Help!

I tried to present remotely to a group of students (10-25 depending on the class I was teaching) and when I sent the link, only one or two students were able to join the presentation. We are all using the same server. Are they unable to join because of this? 

Every time I would have a student who was not in the presentation join it, one (of the two) student would get kicked out. Will I not be able to present remotely at all?

Thanks