[Gameplay] Fiora Ultimate Bug

I have stumbled across another Fiora bug with Blade Waltz. When you are in a teamfight and you target Fiora's ultimate onto someone with Zhonya's Hourglass, and they use Zhonya's, you ult will not do damage to anyone else it hits. For example, if I target my ultimate onto an Ahri during a teamfight, and she uses Zhonya's Hourglass, my ultimate will no do damage to any of her teammates. I've had this bug happen to me twice during an ARAM. I'm not sure yet, if this happens on Summoner's Rift. It most likely does though.