Grouping a shape with a trigger/icon - master slide

hello.

I often group a large transparent square (shape) with an icon to expand its clickable area.

I created a trigger/javascript volume on/off toggle function in a master slide using this tutorial (https://www.youtube.com/watch?v=48-RliZVa4k).

When applying the master slide layout to a slide, the grouping of the square and trigger did not work as expected. 

Any help/ideas most appreciated.

Thank you