AECOSIM CE4 - Mechanical Device Hookup not working

I am having issues with the Device Hookup tool. Previously in SS6 this would produce a temporary, single line path prior to confirmation of the route.

I'm not seeing this in CE4 and nothing happens when I left click to accept, in this case, the two ducts that I am trying to connect.

The condition is a simple one. Two ducts of identical size, in alignment but a different heights.

Obviously I'm missing something and would appreciate any guidance.