Event Handler for template

If I create and Mouse pressed navigation event on my template, sometimes it works when I click, sometimes it doesn’t. I am unable to figure out what I am changing or doing wrong for this…
The “source” should be the entire template root, correct?
If i’m clicking on rectangles whether transparent or not… I am still clicking the source, no?

That is correct. However, if there is any overlapping components or any components inside the template that take the mouse event it won’t pass through to the template.

This is true, unless you do this: