Problem resizing structured activity elements

[BrandonWR]

I am using EA 10.0.1009 and am using a structured activity element to represent a for loop.

What I would like to do is resize the setup/test/body components of the element.  The UI actually allows me to go as far as drag&drop of the dotted lines between these components, but none of the changes ever take effect.  I.e. when I drop, the structured activity element returns to its original size.

To be clear, I can resize the overall structured activity element, but not the components within it.

I have tried a number of permutations beyond what I describe above:
- trying to adjust component size with an empty structured activity element as well as one populated with other elements
- overlaying other elements within the structured activity element and using the auto-resize capability (alt+z)
- docking the structured activity element to other elements (hoping the auto-resize would act differently)

Could anyone advise me on how to achieve an individual resize of the setup/test/body components in the structured activity element?

Thanks for your help.