Why have some words been moved to different levels?

I can’t speak for the specific vocab item, but they’re doing several content changes since a while back now. Among them adding several new items, as well as moving some of them. That’s mostly to do with transitivity/intransitivity where the idea is to separate the pairings to make it easier to absorb them.

You can read more about it here:

But, also outside of this, changes are sometimes made. You’ll have to check their “Content Updates”-posts for specific info about this item, but it should have been announced or will be announced shortly (if it hasn’t).