These two posts were pinned by communities that I follow, but since then they've never disappeared. I don't know if this is intended, but it seems annoying, given that the subscribed tab is all I use.
These post start to get annoying, but I don't knkw how to get rid of them without blocking the OPs for no real reason. :(
Ah yeah, thank you xD
Turns out it was just the instance owner pinning some posts.