xkb keyboard layout not working on certain software

I use a custom keyboard layout which I set up by modifying /usr/share/X11/xkb/symbols/custom as follows:

default partial alphanumeric_keys
xkb_symbols "custom" {

    name[Group1]="Italian (custom)";

    ...  // other keys I have edited

    key <RTSH>  { [        Tab ] };
    key <NMLK>  { [     Escape ] };
    
    include "kpdl(dot)"
    include "level3(ralt_switch)"
};

In particular I have modified the Right Shift to serve as a Tab and Num Lock to serve as ESC.

In most software I use, all the key remaps work as expected.
(This is true also for key-combinations. E.g. CTRL + new_Z => Undo)

On some software applications, such as VSCode, the modifications for Right Shift and Num Lock do not work. (I installed VSCode by using the the official website @Microsoft)

System: Fedora 38, GNOME 44.3, Wayland.