I recently noticed the same posts popping up and they contained the exact same comments but instead of the comment saying 1month old it would say like 3 hours. I asked and some suggested it is karma farmers and they use the same posts and same comments that generated a lot of likes in the past to get karma and once they have a lot of karma their posts are more likely to hit the front page. I wish I could block posts from reappearing but they just slap a new title and don’t show a proper thumbnail and trick users to watch it again.