Need a little help diagnosing an issue with a pcb

[JollySkeletor]

Hey guys, recently got hold of a custom board that features the alps64 pcb by hasu and i'm having some issues with the signal from particular key presses. It was apparently working fine when it was shipped - so something must have happened to it in transit (see pcb below) edit: note that is is just a stock image from hasu's original post



When I press the "a" key, it also registers the "enter" key (i.e k33 also registers k23)
I get the same issue with the "q" key and the "]" key (i.e. k35 and k25)

Additionally the left shift triggers the right shift and the caps lock triggers the escape key (it's supposed to be just ctrl).

So something has happened to the left side of the pcb (right from the image) and it's pretty consistent (the double triggering is one way, i.e. only happens when a -> enter not enter -> a). I have tried reflashing the firmware to no avail - so I can only deduce that there's some electrical issue going on here (my knowledge of electronics is basic at best).

Has anyone seen this kind of behaviour before? I did some basic testing of the diodes that are meant to protect said switches but they seem to be consistent with switches that are working fine (again not an expert so my testing methods could be ultimately flawed).

Thanks in advance.