Why content of communities are missing in other instance?

See screenshot. Example here is !privacyguides@lemmy.ml On lemmy.ml I can see several posts, on lemmy.world, none.

I logged in in both, I joined both, both profiles have enabled NSFW content and language is untouched (so all languages should be displayed).

What is the reason for that and how I get the posts on lemmy.world?