Audition not working with Mono on mixer

Hello!

I'm using the Zoom LiveTrak L-8 with Audition on a new MacBook Pro. The driver is fully installed and the device class is CoreAudio (only option).

When opened the mics read just fine under Default Stereo Input. However, I select Mono and tell Audition which channel input to record on each track individually and for some reason, every track does not want to read.

I've gotten this to work before and can't figure out what's happening. What setting changed in Audition (or the mixer if you happen to know) that I need to set back to?

Thanks for all your help Adobe Community!