Selected track for recording skips tracks mid-recording

Hi, currently auditioning BM3 on a friend's iPad. Digging it but experiencing some bugginess. One problem I have now experienced twice is that while recording onto, say, A1 with the Ashe Kit, BM will swich to recording on B1 in the middle of a take (or vice versa). And the behavior will keep happening until I delete the pattern.

I AM using BM3 with an external controller, but so far all I have done as far as MIDI focus actions is set up the 64 pad assignments and assigned buttons on the controler to play, record, ff, rw, stop, and metronome. So I am not sure if any stray MIDI messages might be causing this. Actually I DO think that the first time I had the issue, I was not using the external controller.

I am sorry if I am missing something obvious or if I did not search the forums well enough. I tried a number of searches with no luck. Thanks.