Controlling members in a Team

I have experienced in my class where my students, all members not admin, are kept being kicked out or disconnected as if on purpose by someone during our voice conference. Also, many members complained of being muted, including me without me clicking the mute icon. I just suspect that some of our students are behind this because those are my problematic students and recently the same students complained of not being able to download their worksheet in the assignments, again only the four of them. This never happens in my 3 other classes.

I know there is no option for them to do this but I feel at least of them is "hacking" the system. Is that possible? If yes, is there a way for us to get to the bottom of this? Or was it just technical glitch? Thanks.