Fullscreen before scene starts

Hello, this may have been answered before, but I could not find it. How do I start my game in fullscreen, before the scene starts, not at the beginning of the scene. When previewing, there is a split second when I see a window, then it goes into fullscreen. If I publish a game to the app store will that little window show before it goes into fullscreen? That doesn’t seem right.

Mobile doesn’t have a “Windowed” mode for apps like this, so it’d start fullscreen.

For PC, you cannot avoid this. However, this is pretty common for a lot of games.

Thanks. That does help.