Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
I’m looking through the thread and can’t see whether this one was ever answered.

Seems like an important one to check based on the specific symptom that GarageBand works but MainStage doesn’t.
Yes, I have confirmed that permission has been given to the appropriate input microphone.
 
Yes, I have confirmed that permission has been given to the appropriate input microphone.
Sorry, it's not clear from your reply, do you have the box next to MainStage checked in the Microphone privacy settings in System Preferences like this?
Screen Shot 2023-01-08 at 7.18.06 PM.png
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.