[Support] Instance-specific Firefox login issue?

Sorry preemptively if there's an actual tech support instance for this space, but I didn't see one linked in !Main.

I can't seem to log into sh.itjust.works on Firefox. I thought it was some weird mobile shenanigans that I've come to expect from phones (mine is current Samsung) but it's also happening on my Mac Mini.

In both cases, it just spins forever when I click log-on. I really don't want to be forced to move instances or use this from Chrome or Jerboa.

Is anyone else having this issue? Anything I can do to fix it on my end?