Upstream removed /etc/sddm.conf years ago. It seems like to me it is now /usr/share/sddm/sddm.conf.d/00default.conf I suggest adding cp -v /usr/share/sddm/sddm.conf.d/00default.conf /etc/sddm.conf To add in a much better defualt config. Like wayland support. Just an Idea Have A Great Day ShorTie
sddm already reads the default config from /usr/share/sddm/sddm.conf.d; there is no need to duplicate it in /etc/sddm.conf.