Portrait Orientation gives Portrait Fullscreen video

[SayaGames]

Hi, I use portrait orientation in my app by the code:

SystemChrome.setPreferredOrientations([
DeviceOrientation.portraitUp,
DeviceOrientation.portraitDown,
]);
If user click fullscreen mode on the player, result is portrait video (shrunk)***

I want if user click fullscreen button, result is landscape (correct ratio of the video). User can manually turn the phone to watch.
How to?
Best regards

(Also, is there any event to enter fullscreen?)

[SayaGames]

I noticed that, removing the "SystemChrome.setPreferredOrientations" declarations (not forcing the specific orientation) cure for the issue. But this time we have to implement on UI for horizontal / vertical layouts both.