So, I've found a solution...
I became pretty sure the issue was with GDM, so I started my search there and found hope in the Fedora forum; using this solution worked, save the "restorecon" part, where my system complained there is no command. Even without it, the other two commands fixed everything.
For anyone who strolls along to this thread, I was able to:
sudo cp -f ~/.config/monitors.xml ~gdm/.config/monitors.xml && sudo chown $(id -u gdm):$(id -g gdm) ~gdm/.config/monitors.xml
Thanks, @WetGeek, for helping point me in the right direction.