Not sure if this was by design and just not noted or something turned on unintentionally.
When using the Popular Searches quick dropdown, it appears that only unread stories are listed. If I repeat the search using the same parameters manually, all stories (read and unread) are listed. If I change the flags to show only unread stories then I see the same results as in the dropdown-initiated search.
My only concern, nit, whatever is that there's no mention in or around the Popular Searches dropdown that indicate the search is for unread stories only.
It's definitely a minor issue but I noticed it, searched and didn't see any other posts related to it, so thought I'd mention it.