[Gameplay] Kennen E doesn't add a stack of passive when hit by hecarim's E

I'm not sure this is a bug but Hecarim's devastating charge should make Kennen able to add a mark of the storm with his lightning rush but it's not the case. Each time hecarim rushed to me i activate my lightning rush to be able to trade but none of those times did it mark hecarim. I find it hard to believe Hecarim can push people without touching them.. idk just feels unintuitive. Thank you for your time.