Help C2 Velocity is broken on my AK

Hey i just recognized today that the C2 Key (nevermind how i transpose it) is much louder than the other notes.
But if i record it in the sequencer it got same volume. with velocity off there is no difference when playing.
never had this issue before first thought the hardware would be affectet but now i guess its something else cause it works fine in the sequencer or is the sequencer correscting the cvalues a lil bit?
pls help i know the manual but didnt find anything helpful