"Eu tenho exatamente os mesmos sintomas em minha caixa com base no xfce 4, o culpado é um plugin de painel xfce4-xkb-plugin 0.5.4.1-1, que eu uso para alternar entre línguas. ele redefine o layout a cada 10 minutos.
do README:
Known limitations and bugs
Currently if one sets any Xkb options, besides the grp: ones they will be lost the next time the plugin is started. Even more - only the first grp: option present in the running configuration will be stored in the config file and thus only it will be restored the next time the plugin is started. This will be resolved in future versions.
the README also mentions an undocumented (well...) config file option called
I edited the file which on my machine was found at: ~/.config/xfce4/panel/xkb-plugin-??.rc
and changed the 'never_modify_config' option to true. i then 'kill -9' the xfce4-panel process which respawned and reloaded the conf file.
the problem disappeared, I can manage keyboard layouts through the xfce4 settings/keyboard menu, and still switch languages using the xkb panel plugin."