Application.Current.Properties are persisting after application uninstall

I use the Application.Current.Properties for persistent storage regularly. I've never had a problem with them.

Now all of a sudden, in my UWP app, the properties are persisting despite the application being uninstalled and deleted.

When launching in debug mode, in the project properties I have "Uninstall and then re-install my package.

All information about the application state is deleted" checked.

Yet, when I launch the app, all the values in the Application.Current.Properties are still there!

I use Application.Current.Properties.Clear() when launching the application, to no avail.

After await Application.Current.Properties.SavePropertiesAsync() I get the following exception:

  Error HRESULT E_FAIL has been returned from a call to a COM component.
  at Windows.ApplicationModel.LockScreen.LockApplicationHost.GetForCurrentView()
  at Xamarin.Forms.Platform.UWP.WindowsBasePlatformServices.get_IsInvokeRequired()
  at Xamarin.Forms.Application.<SavePropertiesAsync>d__60.MoveNext()

This has never happened before. Does anyone have any ideas?