Categorizing- drag and drop materials?

Lissa_xyz

I'm going through my content getting my categories sorted, and having a much easier time now that I know you can drag/drop and it will properly copy/place the item; however, I'm noticing that you cannot drag/drop materials. I can drag a material to where I want it, and the category highlights just as it does with physical objects, but the material isn't actually copied into the new category. Is this intended, or am I bugged?

For example, on the Elven Dress for Genesis, I've dragged/copied all of the physical items, but the texture presets won't budge unless I manually right click > categorize > and click through everything manually.

/edit
Something fixed itself somewhere as I can properly drag to copy materials among categories. I still can't with the Elven Dress though for whatever reason.