If anyone comes across this, I guess the answer is not very useful because it could happen anywhere but there was a cracked solder joint right after the master fader on the submix section. That solved the submix problem. The channel pan problem, it was simply the busses need to be assigned to...
As someone who has used very straightforward hardware/daw mixers in the past, I find the M30 to be somewhat difficult to grasp. That may be because there's something actually wrong with mine or maybe I'm just not understanding how it works. The main issue is the submix. I've got audio coming...