Can't forward X11 apps over ssh since migrating to 13-CURRENT

I don't know if it's just coincidental or if it's because of some change in
13-CURRENT, but I recently migrated from 12.1-STABLE, and now I am unable
to forward X11 apps over ssh. The only app I was accustomed to running this
way was Handbrake. It worked fine before, but now i get this:

$ ghb
Unable to init server: Could not connect to 127.0.0.1: Connection refused

(ghb:87219): Gtk-WARNING **: 13:12:41.281: cannot open display:

I have tried other apps like Wireshark and even xclock just to see, but
they won't work either. Has anyone else had problems with X11 forwarding on
13-CURRENT? If it's working for everyone else, at least I can know it's
probably not 13-CURRENT's fault, and I need to look elsewhere for the
cause. And yes, my sshd_config has it enabled. It worked fine before, and I
made sure to keep the same config.