On Xcode 12.4, the 12 mini emulator gives 2435, 44, 44, 1125 and 375 to the following lines of code:
int screenHeight = (int)UIScreen.mainScreen.nativeBounds.size.height;
int navBarHeight = (int)self.navigationController.navigationBar.bounds.size.height;
int statusBarHeight = (int)[UIApplication sharedApplication].statusBarFrame.size.height;
int screenWidth = (int)UIScreen.mainScreen.nativeBounds.size.width;
int navBarWidth = (int)self.navigationController.navigationBar.bounds.size.width;
Connecting an iPhone 12 mini device and running the same code, the returns are 2340, 44, 50, 1080 and 375.
I connected an iPhone 12 Pro and the return values were the same for the emulator as for the device.
There is a bug... Thanks for the suggestion to connect a real device!