What will be the solution?

We are the virtual music lesson instructor of the class of 45 students. Due to the international existence of our students, all of our classes are offered online. Although I usually serve as the meeting's host, some students claim that after a while the voice becomes subdued. Not all students deal with this, but some do. The meeting must then be ended and restarted, which is a major time waster.

I'm not sure why this is taking place at all. Please look into this situation!