Reordering the Assembly Tree

Hello,

I just upgraded from SW2015 to SW2017 and I am finding all of a sudden that I cannot reorder my assembly tree by dragging features and components.  In all my previous models, I used the following tree order:

Primary Planes

Sketches

Reference Planes and Axes

Parts and Subassemblies

Mates

Now, SW2017 is putting my sketches and reference planes below the parts and mates, and I cannot move them directly beneath the primary planes.  Is this intentional or is there a glitch in the installation?

Thanks,

Robert

SolidworksAssemblies