Boost For Lemmy

No, I didn't say that. I'm unsure where the confusion arises so I'll start from the beginning. And try to clarify my problem.

1. There's a setting that makes it so posts you've already read are automatically hidden. I have this turned on.
2. There's a setting that makes it so posts get marked as read when you scroll past them. I have this turned on as well.
3. There's an option in the drop-down when viewing communities that says "clear read". This button doesn't seem to do anything.

Let's take a specific community, doctor who @ lemmy.world. This community is the main reason I'm having a problem, because usually I'll see a post on my feed from there before I watch an episode, so I want to read it later, but when I scroll past the post it gets marked as read. Now once I've gone and watched the episode, I'd like to go back to the community to read the post I skipped before. Of course that post is hidden, because it got marked as read when I scrolled past it. That's when the button from point 3 seems like it should allow me to unhide the post, but it doesn't work. I can verify that the post does still exist if I just visit that community in a web browser instead of in boost.