xkbOptions layout toggle not working

Help
1

I would like to toggle between de and us keyboard layout. Following the article in the Arch Wiki, i defined the following in configuration.nix:

  services.xserver = {
    enable = true;
    layout = "de,us";
    xkbVariant = "nodeadkeys,";
    xkbOptions = "caps:backspace,grp:win_space_toggle";
   ...

but when i press win + space nothing happens. I also defined grp:ctrl_space_toggle but this isn’t working either.

What am i doing wrong?

2

What WM/DE do you use? Also note the warning at the top of the wiki page:

Note: XKB options can be overridden by the tools provided by some desktop environments such as GNOME and KDE.

3

I’m using awesomewm but have some config files left over from KDE. Could they still interfere?

EDIT: just deleted all hidden files with kde or plasma in them.