[Gameplay] Kennen's icon of E would stay in insufficient mana mode(blue waterdrop)

i just found that in aram with max lv of Kennen's E. if he dies while casting his e, the icon of it would stay in insufficient mana mode until respawn

1. kennen cast his e
2. he dies no changes to other spells, qwr stay in normal gray mode after he dies. no influences from items.