[Bug] Zhonya durring WW ult

Just played a game where everytime I ulted the enemy nidalee, she was able to Zhonya midway through my ult. I can confirm it wasn't just a "well timed" zhonyas and she had no tenacity. It happened about 3-4 times and she also confirmed the same thing after game in lobby chat.

(My ult would go off land on her, and begin doing its damage, then she would Zhonya and my ult would continue on her for the rest of the duration doing no damage).

I don't think this is intended. Just want to bring to someones attention.