The keboard layout is specified in multiple places. The command systemd-localed updates the settings in /etc/vconsole and in /etc/X11/xorg.conf.d/00-keyboard.conf, so to edit the latter file it would be better to use the systemd-localed command.
In addition, kmscon can set the keyboard setting in /etc/kmscon/kmscon.conf, but it is unclear from the documentation which keyboard setting is used if nothing is specified in kmscon.conf.
Then each desktop environment has their own keyboard setting, which usually seems to fall back to using the setting in /etc/X11/xorg.conf.d/00-keyboard.conf, but, again, it is not clear from the documentation if that is always the case.