Updated my in-rack sequencers firmware, now its seemingly a 50/50 chance that if I boot my rack with the midi cable in Poly Cinematic it refuses to respond to MIDI until rebooted with no cable. Caught me out in a live performance last week.
Can't expect Poly Cinematic firmware to deal with whatever hundreds of different sequencers might or might not spit out when they boot up, maybe PolyC firmware could delay opening the MIDI port for 5-10 seconds after power-on to allow any MIDI "noise" to conclude first?
I could try getting a MIDI monitor running to see what is being generated on startup if that helps, my other MIDI modules are not impacted.