Using Modstep to sequence midi

I'm trying to use modstep for all my sequencing, and I see that BM3 has options in the mixer tab for having separate midi channels per pad. So in theory, shouldn't I be able to create tracks in modstep and route each one to different midi channels in BM3? This is what I tried:

Bank A has 4 pads, each pad holds a different sampler instrument that I made. I created 4 tracks in modstep, routed to channels 1-4. In BM3, I set modstep as a midi source, then in the mixer, I chose the 'show pads' option, which allows me to designate which channels each pad should listen to.

However, no matter what I do (and I've tried a bunch of configurations), BM will take any midi input and trigger notes in pad 2. I'm trying to trigger notes in pad 4, which I set to midi channel 4 in both apps, but nope, pad 2 is the only one playing. Is this a bug, or am I doing something incorrectly? I've tried a similar approach using AUM to route midi from modstep to BM3, but it's the same thing. In fact, BM3 doesn't even see AUM as a source.