У вашего броузера проблема в совместимости с HTML5
A look at cool ways to incorporate the current XP11 pop-out windows into your home cockpit as well as a wish list for future Pop-Out development by Laminar Research
I would add that although I mention remembering location in my window persistence discussion, it should also apply to WINDOW SIZE.
See my other videos on how to set up X-Plane External and Multiple views