title: Xamarin.Forms, Prism.Forms, Android Lolliop 5.1.1, Navigation transitions/animations
body: <p>I have a problem when using Xamarin.Forms in conjunction with Prism.Forms (Unity) on an Android 5.1.1 (Lollipop) device.</p>
  
  <p>Specifically, if I navigate to/from forms with "animation: true" those forms do not always work correctly afterward - specifically, the forms are not always updated in response to a PropertyChanged event. The forms work perfectly on Android 6.0 and 7.1 (the only other devices I have available for testing).</p>
  
  <p>If I change all of my calls to INavigationService.NavigateAsync so that "animation" is false, those forms behave properly as long as I do not use the hardware "back" button to exit a form (as this then animates again). I have even created an override of the "UnityPageNavigationService" that overrides the "animated" parameter on calls to "DoPop", "DoPush" and "GoBackAsync" (I am pretty sure that the NavigateAsync method eventually calls one of these for all requirements except in the case of changing the content of a MasterDetailPage).</p>
  
  <blockquote>
    <p>I am pretty sure that this is a Xamarin problem and not a Prism
    problem as having looked through the code on GitHub it appears to me
    that the Prism INavigationService implementation eventually comes back
    to the Page.Navigation.PushAsync(...) etc. methods and I am also
    pretty sure that the Prism navigation service is not intercepting the
    back button and interacting with it.</p>
  </blockquote>
  
  <ul>
  <li><p>Is there any way to disable the animations when navigation is
  instigated by the hardware back button?</p></li>
  <li><p>Is there a way to override the INavigation implementation for a platform (obviously Android in this instance)?</p></li>
  <li><p>Is there a known issue and/or work-around here for Xamarin Forms on
  Lollipop 5.1.1?</p></li>
  </ul>
  
  <p>I am using Xamarin Forms 2.3.4.231, Prism.Forms 6.3 and Prism.Unity.Forms 6.3.</p>