no spdif signal in ableton from motu 828mk3

[peterdejong]

So, I'm trying to run audio from a Behringer DDM-4000 (a scrappy 4-channel dj mixer running 2 vinyl decks and sometimes 2 cdjs/sometimes just computer and phone audio). I'm running the spdif out (16 bit/44.1hz) to the spdif (rca) input on the motu 828mkiii and I can't seem to get any audio in ableton (Live 9.7.1 Lite) when I try to record. I have no problem recording audio from analog inputs on the 828. I hear the spdif audio perfectly fine in my monitors from my main outs. Word Clock is set to spdif, default audio input is set to spdif, already fixed some phasing issues, have tried all the different inputs on the ext ins in ableton (should be ext in 11 & 12, i know motu's cue mix input order is weird...), sample rate is set to 441000. Can't think of any other problems...

Any ideas? Is this just not possible? Do I need a full version of Live?

Secondarily, is this setup convoluted? Should I just suck it up and use the analog outs (was hoping to keep it all digital for clearer audio)?