Full Screen Sidebar with SwiftUI on Big Sur

Adopt the new look of macOS covered how to create a full screen sidebar in AppKit, but I'm not able to figure out how to accomplish this with SwiftUI. Any ideas as to what I'm missing?

Code Block swift@mainstruct MyApp: App {  var body: some Scene {		WindowGroup {      ContentView()		}  }}struct ContentView: View {  @State var strings: [String] = ["A", "B", "C"]  @State var selection: String?  var body: some View {	  HSplitView {      List(selection: $selection) {        ForEach(strings, id: \.self) { string in          Text(string)      	}	    }			.listStyle(SidebarListStyle())	    VStack {        Spacer()        Text(selection ?? "<none>")          .frame(idealWidth: 100, maxWidth: .infinity, alignment: .center)   		  Spacer()			}    }  }}

I already filed FB7776520 in case it's not possible, but I'm assuming I'm missing something since it's a marquee feature. Thanks!

Update: If I replace HSplitView with NavigationView it works as expected. 🤦‍♂️