When I assembled my Pokitto the “B” button didn’t have that “clicky feeling” like all the other buttons. I worked, but it made no sound, and barely moved when I pressed it.
I could fix the problem by separating the casing a bit, but that made the other buttons jiggle, and would often seal itself back up by accident when holding the device.
Anyway, I figured out the problem is that the plastic pillar on the inside of the B button (the thing that actually makes contact with the switch on the board) was very slightly longer than the A button. Only maybe a millimeter, but it was enough to ruin the feeling.
I used a simple nail file to bring it to the point where it is flush with the circular base of the button. It now works perfect!