When I sub to a community, I don’t see all the posts if I’m logged in to my instance. If I go directly to url of the community I can see all the posts.

Is this a federation thing? Is it a setting? for example going to https://lemmy.world/c/askscience I can see everything. But when I sub to it and go there, I only see 2 posts and no matter what setting I choose it’s always just those 2 posts. The site says there are 19 posts, and I can see them from the url. Help?