[GAMEPLAY] Xayah's feather empowered attacks do not hit Illaoi's tentacles

The link is a highlight from one of my recent games. This is just one example, it was easy to reproduce.

After using a spell Xayah's attacks become empowered for a certain number of hits. During this time Xayah's basic attacks can target but do not hit Illaoi's tentacles. Once she runs out of feathers, Xayah can hit the tentacles as expected.

This seems like a bug to me because getting rid of tentacles is extremely important in a fight and unexpectedly missing them can create a lot of wasted time and wasted attacks.

This occurred during a game at 17:57 on 11/08.