Question - I've encountered some unexpected behavior when using both a StackPanel and Button in the Babylon.GUI package. I've created a playground (https://www.babylonjs-playground.com/#V3R633) which duplicates the issues.
I create a StackPanel, and add a button to it, which works fine: I click it, and I can see it is responding to that. I then add a TextBlock. but then the button appears not to be responding to the event. In my actual code, I have a Observable (via onPointerDownObservable.add), which fails to occur: in the playground code, you can see the button fail to trigger the default action instead.
Any ideas what I've down wrong?