Okay so I’ve been able to get communities to load after (but not necessarily as a result of) spamming a mixture of their full URL (e.g. https://Lemmy.world/c/music), their URL without the protocol (e.g. lemmy.world/c/music) and just the community name by itself (e.g. music). The results always turn up on just the community name by itself.

I’m thinking the most likely explanation is that the communities are found by incrementing through the federated instances, and the time it takes is just highly variable (probably due to server load, and possibly the order in which instances are polled?) and my spamming the various formats I mentioned above is simply a way to keep myself occupied while I wait 😆