YouTubeMovie: Width, Height and Locking are ignored by Xojo

I have a XOJO WebApp.

I made a new WebPage, include the “YouTubeMovie” - control, and the URL.

When I test the WebPage, the YouTubeMovie-Control didn’t have the size I made in width & height.

Even when I using the Locking-Controls, the YouTubeMovie-Control ignore it.

Which is the correct why to change the sizes of this control? How can I center it? And how can I locking it, so it will “grow” when the Website will resize from the user.