I've got my M9 syncing up to a master midi clock, but it's slightly slow. Specifically, I can see in bmp in the setup screen, as the master tempo displays what the M9 is syncing to. My computer is sending out 80bpm, but the M9 is fluctuating between 79.3-79.8, back and forth. Any long delays get noticably out of sync pretty quickly. I've tried different cables, midi ports, and midi interfaces, but the problem stays. I've also got two other midi devices synced up with no other problems... any advice?
Yeah, this is unfortunately a known issue. The MIDI sync drifts a bit. There's really not a whole lot you can do about it. One possible workaround is to find a plug-in that converts MIDI clock to CC to control the M9's tap tempo.