Back in the day, KBD75 from kbdfans had an issue with ESD. Luckily mine would just shut off and would work if I plugged it back in. What I did eventually was take all the mouting screws off and isolate the PCB from the case with electrical tape. When its closed and sandwiched in, it doesn't really need the mounting screws at all.

Now they coat their PCBs in some sort of blackness to prevent this.

so what I'm saying is, maybe if you get a new pcb from them, maybe try isolating the pcb from all metal contact. Hopefully they fix their design. They obviously knew it was a thing if they included the ESD protection as stock.