USB output (X32) doesn't match what is heard

Interesting problem … on a Behringer X32 I have routed the Main LR to the USB card and it sends great signal to the live stream rig. However, two of the mic’s that you can hear live in the venue DO NOT have signal through the USB. We had a silent movie for a piano and vocal solo, whereas the rest of the band was crystal clear during the rest of the set.

I’m new to routing on the X32, so I’m guessing we have some weird configuration that simply never got noticed since we only recently configured the USB output. It was just befuddling to hear it live in venue but watch zero signal make it to the live stream rig.

So … hoping this is an easy fix.