Series stopped working?

Hey guys, I'd set Calibre to send series information to my Kobo Aura and it worked fine. Now it no longer works. I haven't changed any of my Calibre settings, though I wonder if maybe some update changed something?

Check out the image below (I apologize for the poor quality. I snuck it during a slow time at work). The first two books (added months ago) show the series between the title and the author. Recently, I purchased more books in the series and they do not show the information.



The same has occurred with other series as well, so it's not just these books.