First, my knight won't gain experience when I attack kingdoms.
Second, I gave my knight a Train with Kay and when I came back on the game the knights experience was back to where it was before I used the Train with Kay. (No, the knight was not assigned to a role.)
Third, I cannot research. It restarted the app on me the first time, then tried two more times for good measures and it gave me an error message both times.
Fourth, it will not let me request help on buildings in alliance chat.

**i have noticed that when I get close to leveling up, that's when the problems with researching happen.
(I am 158 points away from leveling up)

Hope this helps! :-)