I purchased your Pimoroni Console Kit (PSK) from Adafruit Ind. on 02 July, and finally had time to sit down and assemble it.
Unfortunately, I am another customer who has an issue with the down position with the joystick after boot on my OS of choice: Lakka.
I switched my SDcard with my RPi Raspian OS for troubleshooting to test other commands. All default commands with the PSK, and they responded appropriately with the exception of Down. I switched the Up and Down wire placement on the PCB, and the physical joystick was responded with the Down command moving up and the Up command unresponsive, ruling out the wires and the Joysitck as the source of the issue.
Consulting other forum posts (which others have had issue with the Down command), your Support Team had suggested to use a solder to check the PCB connection. I hesitate to do this without your express instruction, if the PCB is faulty then I hope I can return it for a replacement.