[Gameplay] Elise's Rappel does not dodge Chum the Waters

Been playing Elise since blood moon came out, and every Fizz I've gone against has untargetable-penetrating ults. I thought at first that maybe my timing hasn't been right with rappel, but I've tried it many times and for sure, definitely, I am taking the ult damage while I am rappel'd. I think I've taken a few other hits while untargetable, but I can't think of them off the top of my head and those could have been timing issues. Fizz' ult is for sure. I'm thinking this could be a similar issue that occurred a few months ago when untargetables (Fizz pole, Vlad pool) weren't popping projectiles.