Is there a reason why my xcode app runs fine in the simulator but not on a physical device

I am fairly new to developing IOS apps on xcode. I have been learning for the past 2 months or so. I made an app for learning purposes. It worked perfectly fine on many different simulators but the moment I tried launching on a physical device it just shows a black screen. I even tried on another device and it resulted in the same situation. Can anyone explain why or give me a solution. Maybe something wrong with my AppDelegate or Scene Delegate. My app has a build platform for IOS 11.0.