Can't find and join some kbin magazines

I've been trying to join nintendoswitch@kbin.social for a few days. Going to https://feddit.uk/c/nintendoswitch@kbin.social gives me a 404. Using the same URL on a couple other Lemmy instances (eg lemmy.world) seems to work. Is there an issue preventing new communities/magazines from federating properly to feddit.uk?