UWP App Navigate to Home and clear frames

Question

I have a UWP kiosk app that is leaking memory. When I view it running in Task Manager I can see the memory consumption increasing as the app's pages are navigated. This navigation is done mostly without human intervention and is initiated via a seperate system responding to events in the environment, like a car driving past a sensor.

At the conclusion of the events the app navigates itself back to the starting page. I can see that as it navigates the backstack increases and never resets so I assume (and from reading other so questions such as this one) that this is the cause of the leak. I never call Frame.GoBack();

I use this simple method to navigate through the app:

 public async Task NavigateTo(Type kioskPage)
 {
     try
     {
         if (Windows.ApplicationModel.Core.CoreApplication.MainView.CoreWindow.Dispatcher.HasThreadAccess)
         {
             Frame.Navigate(kioskPage, KioskModel);
         }
         else
         {
             await Task.Run(() => Windows.ApplicationModel.Core.CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(CoreDispatcherPriority.Normal,
             () =>
             {
                 Frame.Navigate(kioskPage, KioskModel);
             }));
         }
     }
     catch (Exception ex)
     {
         //maybe a race condition
         Task.Delay(500).Wait();
         try
         {
             await Task.Run(() => Windows.ApplicationModel.Core.CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(CoreDispatcherPriority.Normal,
             () =>
             {
                 Frame.Navigate(kioskPage, KioskModel);
             }));
         }
         catch (Exception ex2)
         {
             HandleError(ex2, TrackedEventSources.Code, false, "Double thread exception", true, "NavigateTo");
         }
     }
 }

So if I want to navigate back to the starting screen I just call:

await NavigateTo(typeof(MainView), aModel);

This works whether on the main thread or a background one.

Is there a standard way in which an application should navigate home so that the backstack is reset to 0? Or is there something I'm doing wrong in terms of how I'm navigating?

I can call:

Frame.BackStatck.Clear();

But this doesn't free up the memory.

EDIT: I can also do this but it doesn't free up the memory (which may mean it's not the frames that are the problem):

public void NavigateToHome()
{

    if (Windows.ApplicationModel.Core.CoreApplication.MainView.CoreWindow.Dispatcher.HasThreadAccess)
    {
        while (Frame.CanGoBack)
        {
            Frame.GoBack();
        }
    }
    else
    {
        Task.Run(() => Windows.ApplicationModel.Core.CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(CoreDispatcherPriority.Normal,
       () =>
       {
           while (Frame.CanGoBack)
           {
               Frame.GoBack();
           }
       }));
    }
}

Answer 1

It ended up being the pages were being held in memory through each navigation. Instead of navigating forwards all the time I need to go back when returning to the start page. Like so;

Frame = Window.Current.Content as Frame;
while(!(Frame.SourcePageType.Name == "HomePage"){
    Frame.GoBack();
}