Lost space with DoubleColumnNaviga… | Apple Developer Forums

Lost space with DoubleColumnNavigationViewStyle in DocumentGroup

DoubleColumnNavigationViewStyle, on iPad, left an unusable space at the top.
It seems to be a navigation bar's title, but the navigation bar code apply to the main navigation bar.
Is there a way to hide, or at least use, the inner navigation bar?

The sample code below reveals part of the screen unused by the App.

Code Block import SwiftUIimport UniformTypeIdentifiers
@main struct RugbyTimeApp: App {
	@SceneBuilder var body: some Scene {
		DocumentGroup(
			newDocument: {() -> ReferenceDocument in ReferenceDocument()},
			editor:		 {_ -> MainView in MainView()}
		)
	}
}
struct MainView: View {
	var body: some View {
		NavigationView {
			Text("Side View")
				.frame(maxWidth: .infinity, maxHeight: .infinity)
				.background(Color.green)
			Text("Hello world")
				.frame(maxWidth: .infinity, maxHeight: .infinity)
				.background(Color.red)
		}
	.navigationViewStyle(DoubleColumnNavigationViewStyle())
		.navigationTitle("Nav Title")
		.toolbar
		{
			ToolbarItem(placement: .navigation, content: {Button("Next page", action: {})})
		}
	}
}
class ReferenceDocument: ReferenceFileDocument {
	static var readableContentTypes = [UTType.plainText]
	init() {}
	required init(configuration: ReadConfiguration) throws {}
	func snapshot(contentType: UTType) throws -> Int {return 0}
	func fileWrapper(snapshot: Int, configuration: WriteConfiguration) throws -> FileWrapper {
		let data: Data = try JSONEncoder().encode(snapshot)
		return FileWrapper(regularFileWithContents: data)
	}
}