Musescore steals my microphone sound when using Zoom

Certainly not a Pro thing as far as MuseScore is concenred, as there is no pro version of the MuseScore program

My wife uses Zoom to teach teachers how to use the interactive panels made by the company she works for. Part of her setup might work for you. She has her computer signed in mainly to be able to see what the students see, but that could be what you have MuseScore on. She has her phone signed in as the camera so those on the call can see her as she works with the panel ( which is also signed in, but that's something else). For her voice she uses a bluetooth headset (not headphones) connected to the phone. Her voice comes through clear no matter what direction she faces, and she can hear if there are questions. It sounds complicated at first, but think about it.

I've never seen this. What OS? And what settings do you see in Edit / Preferences / I/O?

I'm having a similar but different issue. I'm finding that zoom steals my sound from musescore when I try to use my bluetooth headphones. I've been doing a share screen/sound of musescore and then I am also singing. I have no problem hearing musescore, singing, and hearing my students if they interupt me all at the same time when using regular headphones. But when I'm using BT headphones, musescore won't send sound to them. In my preferences I/O, my BT headphones aren't an option. And switching to zoom output doesn't help. Any advice would be much appreciated!

I've worked on MuseScore while in a Zoom call. When you bring up MuseScore, the Zoom interface notes that the microphone is not detected. If you go test your speaker and microphone again, it should pick up your device(s) and communication on the platform should work as normal.