No sound showing up in microphone test

My mic is a Neumann TLM103 connected to my Mac via a Clarett 2Pre USB. Everything else everywhere else works fine (Garage Band, etc). But when I try to test this mic, nothing is coming through Zoom.

If I switch back to the onboard Mac Mic, I get sound. But zilch from the mic I actually need to use for my call in two days time.

Any suggestions on a setting I may have missed? Anyone have a similar setup?

Thanks,

Jason