Hi from Edinburgh - I never actually used (or even knew about) /r/casualUK, but new to Lemmy and looking to add so my subscriptions while I find my feet!
I'm not any kind of expert (got to grips with Mastodon a while ago but new to Lemmy) however I had some similar problems on my other account and it was fixed by making sure my account settings had "undetermined" selected under languages as well as english.
Could be something else in your case (not sure, I can see comments ok when I follow my link) but it's worth a try.
Lemmy.world is an instance - a server that hosts your account and any data.
UKCasual is a community, essentially a subreddit. Its stored solely on the Lemmy.world server
Whilst this community is stored on lemmy.world, if you're logged into another instance you can still see and interact with the UKCasual community, but data remains on lemmy.world
I'm not sure if there's a sync delay between instances etc
Okay. So if lemmy.world goes down then presumably all the communities it hosts also go down? This seems to present a bit of a logistical problem for community longevity. For example, a small instance that creates a popular community across all of the fediverse then has to try and support a large amount of traffic with possibly little local income/support?
Yeah lemmy.world is the instance your account is on, and it's the one this community is on. But you can basically join and interact with communities on any instance.
I'm here. Took a few days as I stood up my own friendica instance first off and it took me a while to realize it doesn't play that well with Lemmy. So I've started my own Lemmy instance now, which was 300% harder than it should have been as the devs aren't keeping the documentation up to date with the config files.
Now that I've used the fediverse it's not as weird as it sounds. But the learning curve is steep and I'm only here thanks to perseverance.