I also was stuck on a similar issue for a little bit, my difference was that I simply wanted to switch from "Ctrl + Shift" to "Alt + Switch".
I figured out that you can edit the settings manually (although not recommended). On my Fedora 42 KDE installation the configuration file is located at /etc/X11/xorg.conf.d/00-keyboard.conf, my configuration looks like this:
Section "InputClass"
Identifier "system-keyboard"
MatchIsKeyboard "on"
Option "XkbLayout" "lv,us"
Option "XkbModel" "pc105"
Option "XkbVariant" "apostrophe,"
Option "XkbOptions" "grp:ctrl_shift_toggle"
EndSection
In my case, I had to switch the line Option "XkbOptions" "grp:ctrl_shift_toggle" to Option "XkbOptions" "grp:alt_shift_toggle", then reboot the system, and now, instead of "ctrl + shift" it is "alt + shift" to switch between layouts.
In your case, I assume that you can simply remove this Option line in this configuration.