I have the weirdest thing with my server -- outgoing federation doesn't work but incoming federation is fine. I've made a test post on a local community that doesn't federate, but I hope this will...

edit: updated to 0.18.5 and seem to be getting the issue again, so I'm making an edit to see if this works

edit: I tried editing this from Infinity to see if it sending an activity would work -- and it did! Maybe it's lemmy-ui?

Nope, things literally started working again.