Kennen Ult Bug

So while playing an ARAM, there was a Kennen on the other team that had a glitch with his ult which was when he did, the ult would be invisible. There was no lighting circle or anything like that. The ult went off and still had a full affect, but my team could not see it. Everyone on my team couldn't see it. I would think that's an issue that should be fixed because we can't tell if he ults or not when he goes in and we won't know how wide his ult is to get out of it before he stuns us. Dunno if other people are having this problem, but yeah. It's something I thought that was worth reporting on here.