Kennen Ult not showing (GAMEBREAKING)

Recently played in a game with a Kennen, Sol, Leona, Lee, Cait, Yas, Thresh, EZ, Reksai, and Kat and part way through the game (like 15 minutes) Kennen started to cast ults and it would not visibly display.

That is rather game breaking, though I don't know really how to replicate it, someone should probably look into that asap.