Strange federation issues

I have started a Lemmy instance on lemmy.praveen.org.uk but I'm having some strange federation issues. Firstly Community Search does not work (unless I'm misunderstanding what community search is) but All search does work.

Secondly, is the Linux Gaming community on lemmy.ml bugged? If I access it through: https://lemmy.ml/c/[email protected] it works but https://lemmy.ml/c/linux_gaming does not (wayback link here). As Linux Gaming is a lemmy.ml community I would think that both links should work and I have not found any way to subscribe to it from my instance.