Encoder socket wrong way round.
If you do this you will have to swap over the connector on the encoder board. Otherwise you will have a zynthian that will freakishly do lots of crazy menu on turning the encoder, and nothing on the press button.
Putting in the caps symmetrically the Two squarish ones on outside of board will produce encoder response that will track one way but not the other.
It does work without the caps (YMMD) and swapping them round is an exercise in futility . . .
I did not say this I was not here…