Wash select 2 not detecting all pulses

Hi.

I’ve added Nayax to our wash select 2 but have an odd issue. At least once a day it’s charging the card and sending pulses, but will end up with “add $1 for <wash name>” on the WS2 display.

I’ve replaced the cpu board due it crediting a quarter as $1.68 (amongst other issues) and the I/O board as we had a couple of the screens fail. I’ve also replaced the ribbon cables that connect the two.
I’ve also replaced the board that sits between the Nayax and the I/O board.

Any suggestions as...

Wash select 2 not detecting all pulses