I found out the solution. It is a kind of bug I think. If I set the webviewer in other screen, it will show correctly. I found out that if you set a button . Click and change webviewer or canvas to visible , and show the content inside instantly. It will not work properly. I found there is two solution. If you insist to one screen (visible toggle method), you have to set a timer to reload the webviewer or canvas once again. I don't know why, But it work. The second method is load the webviewer or canvas in other screen. I am not prefer this method. AI is basically slow in response. It will let user feel much uncomfortable.
Ryan