SwiftUI: Navigation bar of destination view has no background and is not animated on scroll

This is not a full answer to your question, but a temporary workaround: add top or vertical padding to your list on the child view, depending on your preference. This is what I have been doing until there is a better solution.

This will at least make the content scroll under the navigation header with a proper background rendered behind the header. It doesn't have the nice animation to make the title smaller.

struct DetailedView: View {
    var body: some View {
            List(0...25) { number in
                Text("This is \(number)'th row")
            }
            .padding(.top)
            .navigationBarTitle(Text("Destination View"))
    }
}