cant disable a lagging key on blackwidow v3 keyboard

i have a problem with the circle button top right on razer blackwidow v3, it is lagging and presses by itself, i cant watch a video without my hand pressing that button, and the thing is i cant remap it from razer synapes because it tells me (this key cannot be remapped) for some reason every key is remapped except the one i have a problem with. i just want it disabled ):