title: Xamarin Shell Raise Ambiguous Routes matched Exception
body: <p>In Xamari.Forms, I use the following route declaration in <em>AppShell.xaml</em> :</p>
  
  <pre><code> &lt;FlyoutItem Title = "Toolbox"
               FlyoutDisplayOptions="AsMultipleItems"
               Route="Main"&gt;
  
        &lt;ShellContent Title = "Toolbox"
                      ContentTemplate="{DataTemplate Views:Toolbox}"
                      Route="Toolbox"/&gt;
  
   &lt;/FlyoutItem&gt;
  
   &lt;ShellContent Title = "Parameters"
                 ContentTemplate="{DataTemplate Views:Parameters}"
                 Route="Parameters"/&gt;
  </code></pre>
  
  <p>In the <em>AppShell.xaml.cs</em>, I add programatically a contextual page navigation for the <em>Toolbox</em> page:</p>
  
  <pre><code>public AppShell ()
  {
      InitializeComponent ();
  
      Routing.RegisterRoute("Toolbox/TBOuvriers", typeof(TBOuvriers));
  
      BindingContext = this;
  }
  </code></pre>
  
  <p>When I try to display the contextual page navigation from the Toolbox Page:<br/>
  <em>await Shell.Current.GoToAsync("//Main/Toolbox/TBOuvriers");</em><br/></p>
  
  <p>I get this Exception :<br/></p>
  
  <blockquote>
    <p>System.ArgumentException: Ambiguous routes matched for: //Main/Toolbox/TBOuvriers matches found:<br/>
    //Main/Toolbox/TBOuvriers/TBOuvriers,<br/>
    //Main/IMPL_Toolbox/Toolbox/TBOuvriers<br/>
    Parameter name: uri</p>
  </blockquote>
  
  <p>Just before the call, I can see those values for the Shell variables : <br/>
  <em>Shell.Current.CurrentItem :  "Title = Toolbox, Route = Main"<br/>
  Shell.Current.CurrentState.Location : "{//Main/Toolbox}"<br/></em></p>
  
  <p><strong>Which seem to be the expected one's.</strong><br></p>
  
  <p>If I try to display the page with this call: <br>
  <em>await Shell.Current.GoToAsync("TBOuvriers");</em><br>
  I also get an Exception :  System.Exception: Timeout exceeded getting exception details<br></p>
  
  <p>So, What's the problem ?<br>
  Where does those routes come from ?!?<br>
  Why is the Toolbox page 2 times registered ?<br></p>
  
  <p>All ideas are welcome !</p>
  
  <p>Best regards</p>