Am I misunderstanding these features or do they just not work?

I have "Show Read Posts" toggled off and "Mark Read on Scroll" toggled on. I would think that after scrolling past a bunch of posts and then refreshing that would then clear those posts from my feed, but it doesn't seem to be working. Am I misunderstanding this feature? And if so can we get something like it? I do not want to see the same thing over and over again but I also don't want to manually hide every post.