I tried all the usual fixes - swapped usb ports, cables, restarted obs, mac. Sound works on other devices, like through my webcam but for some reason it won't take the sound from this mixer anymore. I tried recording to see if it was just the meters but no, no sound is coming in. Now, all of a sudden, with no settings being changed, the audio is going through the mixer fine but not showing up in OBS through the input meters.
I'm using a behringer mixer (x1204usb) - Everything was working fine and I've done a number of live streams with this mixer and OBS.