Created attachment 169882 [details] Where you have to apply it right now Using a PIN code as a password (Windows like). Changing NumLock to ON in Keyboard Settings should also change it for SDDM (login screen). Or at least offer to change it for SDDM as well. I had to use internet to find out how to enable NumLock on login screen and no way I could find it myself in Settings... A small button "Apply Plasma Settings" in a hidden (under Color and Themes, I'm expected to find it in any place, but in Color and Theme, since it is a keyboard button and not a color nor theme...)
At the moment it has to be the way it is for security reasons, due to the way SDDM works. If and when SDDM becomes a KDE project and gains more integration with the system, we can sync settings instantly rather than in this manual way. But that seems to be a long way off, so for the moment it has to stay this way, sorry.
At least you could add a hint to keyboard setting, how to enable in for SDDM.