ctrl+alt+[ doesnt work in ESP qwerty

[Ziruxltd]

Hi,
im having a really annoying problem where i cant type "[" in a code file. i use a ESP qwerty so to use that character i need to press ctrl+alt+"[".
my keyboard work perfectly and this key work in any other program, navigator or even in atom's setting tab...
it is really annoying to learn python with this problem.
in other hand ctrl-alt-] works perfectly...
thank for any help.
what really piss me off is that stop working suddenly

EDIT: i find that if i press "num lock" key it work again...