Midi external control jankiness

I’ve been having this problem that I don’t understand regarding external midi control. Often when Ive first started up my machines, the AK will not send midi to my Volca FM, even though the midi channel is set correctly. I’ll play the touch keyboard on the FM itself and I get sound, but playing the keys in midi ext mode doesn nothing. This morning it happened and it didn’t work until I unplugged the midi cable and re-inserted it. Other times, I scroll thru the midi channels and it finally works on the second or third pass. Can anybody explain why this is happening?