I don’t see an edit button, sorry for the self-reply.
Update: I am still unable to get it to work with Material Parameter Collections. The only thing I found was this old post from 2016 that seems to describe a very similar problem. Back then it was related to a certain version of Android and got fixed: UE-26674 with this commit.
I doubt it’s the same thing since it was fixed back then, but the problem is still very similar.