https://www.ericsbinaryworld.com/2015/05/26/fedora-22-upgrade-part-2-tanukimario/
Turns out that the issue was the Fedora SDDM theme. Once I changed that to the default KDE theme everything worked. I wonder what I need to do to get the Fedora theme so that works as well. At least I know for future computers what needs to be done.