thanks for the reply
you said that “You have to force it with a p-lock to send it again” but the message is already p-locked and fails to be sent anyway… not always, it happens randomly (no probabilistics involved)
it was changed in 1.20 or maybe earlier, so that it can’t send the same message twice, even when p-locked.
prior to this change, it was possble to use a p-locked prg chng as a reset after messing with the external synth’s params. a prg chng p-lock set to 4:4 condition gave you 4 bars of knob twiddling fun (bass station 2 here) before the program was recalled. it was fun. i have no idea why it was changed.
for the same behaviour now, you need to alternate between 2 program changes: add the prg chng message you actually want (e.g. 20) to step 1, and then any other prg chng message on the very last step (e.g. 21) to quickly change away from and back to 20.