Not sure if it’s related but I’ve noticed a couple of smaller communities from other instances which aren’t accessible from programming.dev any more, Imaginary Witches and Imaginary Fairies. They give the very helpful error “unknown”, this might be a fun one to try to track down. They’re accessible on the source sites (1, 2) and other communities from those instances seem to work.
Ah, you’re right. I think I see what happened there, I hit those links from a sidebar in a community with
href="imaginarywitches@lemmy.dbzer0.com"
which breaks if you’re on a post page instead of the community page. Easily fixed though, I’ll ping the mods of that community.