Hello Michal, please check this article: https://www.nomachine.com/AR11K00740
You can try putting the following in the .profile of the user, to force the setting, or find a way to let Yast automatically apply your setting when you login.
setxkbmap -rules evdev -layout fr
Note that this appears to be a Yast bug. I don’t see any reason why it should “forget” about your setting once you have set the keyboard in Yast,