Microphone input level stuck at zero

[sleek]

Im running the latest client of zoom, on Mac OS 12.1. Attempting to use a Black Magic Design ATEM Mini controller, to feed HDMI Video, and Audio, into the computer over USB. Now Ive tested and my Mac fully sees the incoming audio and video feed no problem and with full clarity. 

When I set the zoom settings, I can use the Black Magic Webcam correctly, however when I try to use the Blackmagic as the microphone, it allows me to set it, but the input volume slider goes to zero. When I drag it higher, it automatically goes back to zero as soon as I release it. Interestingly when I hold the slider higher, zoom can see the audio data on the green volume bar. 

Also note I have auto volume disabled. I need this fixed ASAP as I have a broadcast on Friday.  PLEASE HELP!

[BMSSTECH]

I have the same problem but doesn´t when I use the free session on 40 minutes. Don´t know if this count