@Freudon I don’t know whether or not this is helpful but I had similar sounding issues with a controller - I sometimes had to press a button once and sometimes twice before cubase responded.
When I put Midi Monitor on it I discovered the controller was sending the values 0 and 127 on alternate presses. I was trying out scripting so had to deal with it there but might be helpful for your situation too?
More info here, good luck.