So I noticed something odd in my queue today. Many, but not all, of my shows are listed as if I have not started to watch them. But when I open the dropdown to show the individual episodes, they're properly marked as watched.
This happens on my PC as well as my Android devices, so I do not think it is device specific.
Here is a screenshot with two series behaving this way. The thumbnail for Kyousougiga indicates episode 1 is not watched, but when I drop down, it shows me up to episode 3, which is correct.
Another example here is YuriYuri. I've completely watched the whole series, but the "next up" markers would tell me otherwise.
The reason I even noticed this is because I was watching a two-season series, and the final episode of the first season did not properly jump to the first episode of the second season, which it normally does. It just sat there as if I never even watched it.
Hige sceal þe heardra, heorte þe cenre, mod sceal þe mare, þe ure mægen lytlað