debounce is a keyboard firmware issue and one the z15s are known to have
I have replaced my switches with khali box pinks and its reduced the occurrence of  the issue but not eliminated it ( have validated this by removing the switches and installing a trust omron switch and validating the input with winpcap the problems are in the keyboard firmware not in the switch (well mostly some cheap switches don't behave as nice and make the issue worse but thats  why we have debounce ) evga needs to switch to a defered_pk_debounce or fine tune the eager_global they seem to be using now :( )) 
 
it seems like evga has just decided to abandon accually devloping there keyboard firmware and made the mistake other cheap brands have gone with and trust that the microcontroler vendor they have selected knows what they are doing (spolier they don't ) 
 
evga keyboard owners just need  to hope the zmk/qmk will support the mcu in the future as EVGA clearly has no intention of supporting the product OR none of the engineers need to live with this thing for more then a day so they don't care about accaually making meaningful improvements to the core keyboard software particuarlly the really aweful matrix scan code including in the NXP LPC5516 mcus sample libs. the  NXP LPC5516 is a really good chip hardware wise sadly the samples and default matrix scan setup is just plain substandard compared with other devices on the market