CONNECT - Constraints removed when feature changes?

Hi everyone, 

and I are working together on modeling an overhead sign structure that has many different variations with many different components. I am currently working on a truss system that is one part of the sign structure and I am running into problems with getting one section of the truss to move as the variables that drive the feature change. 

As shown in the video I attached, I can change the height of the truss (driven by the span length) and the middle diagonal strut moves with it without a problem. However, when I change the number of panels that the truss segment has, a constraint is removed from the middle diagonal struts. I am assuming this is the angle constraint, as it disappears once I apply the panel change. 

If anyone could offer an explanation and/or help, it would be much appreciated!

Thanks,

Shannon Simcox and