It's normal and actually kind of cool by design - the 'fediverse' is basically a bunch of different servers (instances) that can all connect to each other. I'm on Lemmy.world, my other account is on midwest.social, but when I'm looking at posts from all communities on either of those I see more or less the same stuff from all the other communities across the other instances.

But some instances have a theme, like Midwest.social is kind of intended for people from the midwest, but anyone can join. Lemmy.ml is kind of a communist hangout. Solarpunk(spelling) is a lot more eco-conscious than other instances.

You can join any instance you want, sometimes after you join an instance you notice a theme that doesn't really vibe with you, but you can join a more 'vanilla' instance, stay on your current instance, or look around for some instance that's really into whatever you're into.

But at the end of the day your credentials on an instance are basically a passport for all the other instances, and it's mostly gonna be a legit good passport.

That said, if an instance goes to crap from bad moderation or from horrible viewpoints or culture, other instances can basically block it, and if you're on an instance that becomes defederated your basically cut off from all the other instances, so you better go find a better instance, but that doesn't happen all too often