For anyone wondering why they still see the post, there's currently an issue with post deletions on Lemmy: [Bug]: Lemmy 0.18.2 instances are not federating deletion of a post by user who created post #3588

By selecting "Delete" OP deleted the post only from lemmy.world, his home instance, and lost access to the post. He cannot see this post nor further respond to it.

I had the same issue this morning, which is how I know about it.