Like the login screen. You can’t change that at all, whether it’s the background or the default zoom level, it’s part of the system packages and can’t be fixed.
in /etc/fstab (ublue-kinoite, ymmv):
# enable sddm write accesss and therefore good themes
/var/sddm /usr/share/sddm none rbind 00
in /etc/fstab (ublue-kinoite, ymmv):
# enable sddm write accesss and therefore good themes /var/sddm /usr/share/sddm none rbind 0 0