Hi, and thanks for sharing the video and explaining your setup!
I have recreated it, and I got the same behavior. From what I understand, your expectation is that the Yellow Container should only become draggable when you grab that dedicated Icon Container handle. But as you have shown here, the container remains draggable everywhere, indicating that the setting to disable the handler on the main container isn’t being respected.
I will register this as a challenge so the platform team can have a closer look and see if this is a bug, or something that would need more clarity in the documentation. Again, thanks for reaching out!