I haven’t dug into the docs so I’m not sure if this is a feature or a bug, but I’ve noticed that old posts will never get pulled into my instance after I subscribe. So a sub can appear empty, but then I’ll click to go to its home instance and it’s full of posts. Lemmy only syncs new posts upon federation (but again, not sure if that’s intended/expected).
This is the biggest usability problem for me on Lemmy right now. I don’t want to hop between instances.