Are some instances/communities closed off from others? - eviltoast

Still trying to get my bearings here.

My account is through Lemmy.World and when I visit the Movies and TV community through lemmy.world/c/moviesandtv@lemmy.film, I only see a few posts. But when I visit https://lemmy.film/c/moviesandtv, there’s a lot more activity.

Did I mess something up in my settings or is this normal? Do I need to have multiple accounts for other instances?

Thanks, y’all.