Quote Originally Posted by jsberrios View Post
That solved my problem. The only problem is in that every update, I have to uninstall sddm. A minor inconvenience, but at least it is working.

Thank you so much for your help. :-)
Just use zypper and al (add lock) to sddm, but you should be able to set via;
update-alternatives --config default-displaymanager
and select you login manager.