Are these completely different posts because they're in different Lemmy instances? Why don't the two get "joined" together? Do they look separate because the user just posted them twice in different instances, or there's some "per instance" comments going on?
Beehaw banned 5 users from lemmy.world of like 20,000 and decided to defederate (block) the entire instance (server). You’re posting on a copy stored locally and only other lemmy.world users will see your comments.
Yup! Any copies of posts that came from Beehaw will still be available on this instance, but no interactions/comments/etc will be copied back to Beehaw. Anyone else on this instance will be able to interact with you, though.
Correct, you will only see posts by other users on lemmy.world and only they will see your posts. You basically end up with an entire different community, just one that shares the old name. If Beehaw ever re-federates with lemmy.world, than the two communities will become one again.