Oh, that's probably the app. So, the way Android does infinite scroll, it takes a lot of resources to create a "view" (the thing that holds the details of a post), so as you scroll, when a view goes off screen, it gets reused instead of destroying it and creating a new one. This is called a recycler view. When a view gets recycled, it is supposed to replace the details that are unique to each post (title, image, etc.) and keep any other detais (any text that might be common to all posts, any sub views like upvote and downvote, etc.). But if your logic isn't right, sometimes something might get kept instead of replaced when the view is recycled.

I remember making this mistake the first time I used a recycler view back when I was working on my senior project in college, many years ago now. I don't remember how I fixed it or the exact details around why it happened, but I know that I did fix it at one point.