I'm having the same issue as those above. 7/13 completed, and tried a few extras too. Doesn't help that there's no indication of which the system thinks I'm missing.
I am having the exact problem. I am playing on an iOS devise the 1.13.0 version of the game on production1 server (ID um6010831 | 5930732). No matter how many champions I ascend, the total count of the event does not increase.