Net sys - ductwork design

I have number of issues with he package 

! Have a ductwork system where the duct work changes from 400x400 to 400 x 200. I fixed the ductwork to the duct indicated but the results only show it up as all the same size. furthermore the labels added shows it as the wrong size, even though it is fixed. Any thoughts.

Also, when changing heights in the room, it appears impossible to fix the vertical piece of duct between the 2 levels as it cannot be selected to fix