title: SwiftUI - Navigation bar button not clickable after sheet has been presented
body: <p>I have just started using SwiftUI a couple of weeks ago and i'm learning. Today I ran into a into an issue.</p>
  
  <p>When I present a sheet with a navigationBarItems-button and then dismiss the ModalView and return to the ContentView I find myself unable to click on the navigationBarItems-button again. </p>
  
  <p>My code is as follows:</p>
  
  <pre><code>struct ContentView: View {
  
      @State var showSheet = false
  
      var body: some View {
          NavigationView {
              VStack {
                  Text("Test")
              }.sheet(isPresented: self.$showSheet) {
                  ModalView()
              }.navigationBarItems(trailing:
                  Button(action: {
                      self.showSheet = true
                  }) {
                      Text("SecondView")
                  }
              )
          }
      }
  }
  
  struct ModalView: View {
  
      @Environment(\.presentationMode) var presentation
  
      var body: some View {
          VStack {
              Button(action: {
                  self.presentation.wrappedValue.dismiss()
              }) {
                  Text("Dismiss")
              }
          }
      }
  }
  </code></pre>