title: Updating UI BeginInvokeOnMainThread not reflecting immediately
body: <p>I am showing activity indicator after clicking login button until redirecting the user to another page, to make them understand some progress is going on. But after clicking login button Activity Indicator is not shown immediately, it is shown after few seconds,</p>
  
  <p>Why its so? To reduce that delay only I am putting activity indicator...</p>
  
  <p>My Code:</p>
  
  <pre><code>async void loginButtonGesture_Tapped(object sender, EventArgs e)
  {
       Device.BeginInvokeOnMainThread(() =&gt;
                      {
                          loadingPanel.IsRunning = true;
                          loadingPanel.IsVisible = true;
                      }); 
  }
  </code></pre>