Let’s say you are reading this very valuable post of mine here. And you can tell even after reading just a word or two that you want to mark it unread right now without further ado.
Down at the bottom of the screen we see
“Share Bookmark Flag Mark unread Reply”
OK, we click “Mark unread”, and yes, it indeed marks it as unread.
But then we get sent to the site’s homepage.
Somehow it is assumed we want to leave the page and go somewhere else.
Discuss this on our forum.