weird mapping in some cases and no shift

[warriorCavt]

hi, I have an Logitech Y-SAE71 SK-2930 PS/2 keyboard, and it has an F-mode (that is basically help, word, excel, powerpoint and some other 2000s stuff) and additional buttons (that work as expected), but I have a problem; ~ is nothing, NumPad enter is +, [+] is [,], [,] is [;], [;] is ([), (]) is [^], [^] is [6], etc. etc. It's like { Polish, but not [Programmers] (normal layout with diacritical under right Alt), but just like s*** of type: [-] is A with a tail, and [=] is C with a small slash [/] on top }. Not forgetting the "CAPS LOCK syndrome", I mean all the letters are uppercase and can't type [!] to [)] etc. I tested this keyboard on a computer (without drivers) and it works as normal PS/2 keyboard. Without drivers means when I press additional buttons on top and left, it's typing just some letters. Why doesn't this map good?
By the way I'm using u8g2 library for 128x64 SH1106 OLED to display the characters instead of an LCD, code page ASCII.