Starting iOS 13, UIWindowScene was introduced as part of the iOS app lifecycle, and part of the app's setup that was previously done in the AppDelegate was moved to the SceneDelegate.

However, GlassWindow::_1createWindow still uses the screen bounds to initialize the UIWindow:

CGRect applicationFrame = [screen bounds];
GlassMainWindow * mainWindow = [[GlassMainWindow alloc] initWithFrame:applicationFrame];

but when there is a SceneDelegate in the project, this should use the UIWindowScene:

UIWindowScene *windowScene = ...
GlassMainWindow * mainWindow = [[GlassMainWindow alloc] initWithWindowScene:windowScene];

This will also start the path for bringing the multi-window support to iOS (specially needed for iPadOS and visionOS).