This appears to be new functionality, and it can be frustrating at times. I have webmaps with a lot of group layers, whenever I add a new layer and I want to reorder the layers, for Exp: Drag the layer to the bottom of the layer list.
As I drag the layer down to bottom, all of my collapsed layers open up, and hinder me from being able to reorder layers in one drag. I might have to drop the layer into 2 or 3 different group layers, scroll down a little then drag the layer some more before it makes it to its destination.
