[GAMEPLAY] Poppy immune to Varus ult

I was playing Varus, my main. Poppy came in and when I tried to ult her it just went through. So I thought, maybe she didn't ult me. But then another time in the same game i was the only one around, clearly saw the ult and watched it go right through. She was Noxian and I was Arctic Ops.

I have not been in this situation again to reproduce.