So, I think I figured out why my app is freezing up or unable to choose a mic. Anytime my Mac is connected to an external display with a mic attached to the adapter, it freezes. Similarly, if I disconnect the Mac from that, it again freezes. If I’m using it on the Mac, I don’t have a problem. So what I do is whenever I try to connect to the external display, I kill it and restart it, and it starts to work.