How to make foliage grass change material by pressing button?

Hi! In my game I need to change material of grass foliage by pressing button. I made a simular blueprint but only for foliage trees and it works perfectly.

But when I want to do the same with grass (I even made a different component class for my foliage grass), it just doesn’t work. This blueprint even can’t see any grass on level at all.

Maybe there is another way to do it? Or mb I made a mistake somewhere? ._.