Hey there! Sorry about this one. It was intentional, but for those who haven't before viewed this page it will look odd.
"Recent unread topics" was buggy and a lot of people were complaining that it often didn't work. That's because it was "recent" but the way the software decided what was "recent" didn't match up with what a lot of people expected.
There is another page available in the software which is just "unread topics" aka every topic you've never read. This seemed to be favoured over "recent" because it just gives you an update of all the topics you haven't seen, rather then deciding for you what is "recent" (which was sometimes only a few hours depending on your session length).
So when I implemented the Mentions tab I also took the time to switch the topics you can choose from Recent Unreads to just Unreads.
Those of you who have never visited the Unreads page before will have a lot of backlog. But this is an easy fix and will only occur on the first time you view this page. My suggestion: from the new Unreads page, open up all the topics that interest you and when you're done, click "mark all topics as read".
You'll never see the topics from last year again unless they are updated. Hope that makes sense.