zoom q2n

I'm live streaming to YouTube using a Zoom Q2n. The video is great but OBS doesn't recognise the Q2n when I add a audio input source.

And I can't seem to get this all flowing right. For starters, the Q2n cams all seem to hook up OK, but the audio from the L20 Livesound deck is nowhere to be found. I have the drivers installed on everything and all the firmware is up to date. The cams are routed through a pair of powered USB...