This is the nature of a defederated website. There are multiple hosts who all act independently, but have decided to source from each other. Upvotes come in from instances you aren’t on who refuse deletions or process them on a delay.

This means that Lemmy is very difficult to pull information back from, if it’s even possible at all. There are no doubt instances that are almost solely functioning as archives as well that may not even make themselves known except through requests to maybe only one ither instance. It’s great for anticensorship, but not great if you say something goofy you didn’t mean and are now getting downvotes from the instances that don’t believe in edits or whatever it may be.

Deletions not be honored is also pretty common generally, because there are accounts who create posts and then delete their accounts. On reddit it’s throwaway accounts, but on lemmy.world at least it destroys the posts permanently and then all of the engagement is locked under the nonexistent post which will be purged.

I think the best balance is instances allow deletions by admins/mods/the user, but do not allow deletions for account purging by the user. I don’t know how many flags there are in the data transmissions between instances to know the origin of the action or what button the user clicked.