In your Audio Settings second image I see you managed to get it set to 16/44 .. this was likely the cause of the initial issue; it was trying to use 48 (mixer) & 44(RB) which didn't mix..
Also, just as a side note/heads up, you have Input for MONO set to Left, so when using the mixers output you will be recording only the left channel (which is OK in many situations).
Just something to remember moving forward.
RB is kind of tricky for L/R to some people, but once you understand how it works you'll get it.
Usually Input 1 is left side, Input 2 is right side, etc (and the panning on the mixer itself can override this), so if you get weird issues when you go to actually record that may be in play.
You change that setting to Both when troubleshooting to narrow down where the issue lies.
The Caveat is IF the target track is a MONO track RB will record 2 tracks (L/R - Both), allowing you to see which side your signal is coming in on.
Last edited by rharv; 01/04/25 08:20 AM.