Audio- Microphone issues

[JBoroucho]

I'm a new Pro user.

Signed up for Pro because I had hoped it would solve my audio-microphone issues. I am a music teacher and teach 95% of my lessons online using Zoom.

Mysteriously(?) the function that allowed me to hear my students play their musical instruments live during our lessons seems to have gone away, or its service level has significantly degraded.

So now, I can't hear my students playing their instruments. Or, what I can hear, cuts in and out constantly preventing me from truly hearing a student's performance (which is critical when you teach the way I do).

To add to my frustration (I have had to cancel lessons two weeks in a row; this is seriously impacting my ability to do business), I cannot seem to get telephone or even chat support from Zoom Tech Support. I thought my Pro subscription would give me these advantages.

So, I'm appealing for help. I don't think my business can tolerate 3 weeks of lost billable hours. Please help me ASAP!

[ThomasHerrmann]

Happened to me that the button I use for this disappeared. I reactivated it in settings. 

[JBoroucho]

Where in the Settings do you reactivate the button? And, what is the name of this button?

I have "Original Sound for Musicians" checked, and so do my students. That isn't solving this problem.

[ThomasHerrmann]

Aaah, yes that's the button I use too. It happened a few times that it disappeared and I had to re-activate it in the settings. So the functionality must have changed. 
I only use it when I use my gong at the start of meetings - it makes the sound last looooong instead of being cut. Sorry it does not seem to work for you now. Should be a support issue with Zoom I recon. Good luck!/Thomas