Bad-looking app opening on iOS

I recently deployed my game on my iPad, but after I clicked the icon, the app opens in a bad-looking way. Firstly, the icon is enlarged into the size of the screen, then the splash screen shows up (then the game loads). However, other apps on my iPad doesn’t have such problem. Upon clicking on the icon, their splash screen shows without the magnification of the app icon. Some other game developed with UE4 seems not having this problem.
Anyone knows why?