Hi,
the keyboard action of my Sub 37 did behave strange in a way that Black keys had to be pressed harder than white keys, and the action of the White keys seemed not to be balanced over the 3 octaves, so I tried this:
1) Press every key very hard, hit it like a piano, several times.
2) Then start with normal pressure, hold every key down and -> Maximum aftertouch.
whithe keys will show a bit of movement at their mountpoint near the Panel. black keys shall be pressed near their mountpoint, they will move down a little bit at their end Position.
It seems that the keyboard needs an Initial massage to work properly.
Now the keyboard action is equal for every key !