Audio input from external mixer not coming thru to software?

Hey all,

So I am somewhat of a novice to both the Mac OS and DAW work in general, I'm hoping someone on here might have an idea.

I have an external 32 channel (in and out) mixer hooked up via USB. My new iMac sees it, and shows all 32 channels for input and output. Says "The selected device does not have any (input/output) controls." Which seems obvious to me, as levels and all that jazz would be controlled from the mixer. The iMac is correctly sending output audio thru the mixer which is awesome, I get audio from my monitors and see the levels moving for example if watching a youtube video.

From the Sounds menu under System Preferences when I look at the input tab I also see the levels dancing around when I play on my keyboard which is wired to an input channel on the mixer. However, and the problem is, thru any software I use (Reason 10.2 and Ableton Lite) even though I have checked about 3 dozen times that the input is on the mixer device (X-USB) and have the correct input channel selected (both software systems see all 32 channels of in/out), that no input actually comes into the software at all.

I'm sure this is just a configuration issue on my part and not an issue with my computer, but I'm terribly confused and was hopeful someone here might know what the problem is.

I am on 10.14.1 Mojave. iMac 27" -- i5 3.4, 8gb ram, 1tb