numlock is not restored on startup

as the title said: Even when clicking "Restore num lock state on startup", the state is not restored.

Actually, what happens is that the previous state is not saved. I can verify that in the file ~/.config/xfce4/xfconf/xfce-perchannel-xml/keyboards.xml, the value of Numlock property is never updated on exit.

I usually shutdown my computer via the logout menu, or with systemctl poweroff command. Neither of those workflow will trigger a save of the current Numlock state.

I can confirm that simply logging out of xfce (and therefore returning to lxdm in my case) will trigger the saving of numlock state.