Sending program changes

Hi,

I have noticed a strange behaviour when trying to use midi keys to send Program Change instructions to am external device; when changing program numbers using the dedicated knob, I can see the programs changing in realtime on my device, everything seems to work just fine. But when I just hit the midi key, it doesn’t send the program change instruction. What Am I doing wrong ? My goal is to use two midi keys to toggle programs on my external device. I used midiOx to make sure the problem was not on my external device and it confirmed that the digitakt was not sending Program Change when the midi keys where pressed.