Setup with dual Yeti Mics causing monitoring output to be muted

[FastEddie]

I Live Stream Masses for our church. For about a year we've been using one Yeti microphone, which has worked pretty well. Recently we added a second Yeti to adequately pick up the audio from a Lector at a lectern. Since then I have an icon of a muted speaker that shows up right in the middle of the screen superimposed over OBS and if I try to unmute it I can hear audio for a second and then it immediately mutes again.

Anyone ever have this issue? I'm on a Macbook Pro running BigSur 11.2.3.