Back arrow does not work when UWP launched from WinForms app - winrt-xaml

Question

So we are integrating the old with the new.
I am launching my UWP app from within our WinForms app.
When I navigate around the UWP app, the back button does not work. When launching the UWP app normally everything works fine.
Here is my winforms launching code:
Uri uri = new Uri($"companies:");
//see declarations in package.appxmanifest in winten app.
string targetPackageFamilyName = "81e1fc62-68df-45f5-ac35-c86d1277e2db_2zt4j53vqbz02";
// see added protocol declaration in package.appxmanifest in win10 app
var supportStatus = await Launcher.QueryUriSupportAsync(
uri,
LaunchQuerySupportType.Uri,
targetPackageFamilyName);
if (supportStatus != LaunchQuerySupportStatus.Available)
{
var msg = "Can't launch because the app we need is " + supportStatus.ToString();
}
else
{
var options = new LauncherOptions { TargetApplicationPackageFamilyName = targetPackageFamilyName };
var success = await Launcher.LaunchUriAsync(uri, options);
}
And here is the receiving code
public override async Task OnStartAsync(StartKind startKind, IActivatedEventArgs args)
{
if (args.Kind == ActivationKind.Protocol)
{
ProtocolActivatedEventArgs eventArgs = args as ProtocolActivatedEventArgs;
switch (eventArgs.Uri.Scheme)
{
case "companies":
NavigationService.Navigate(typeof(Views.CompaniesPage));
break;
case "company":
NavigationService.Navigate(typeof(Views.CompanyEditPage), eventArgs.Uri.Query);
break;
case "query":
NavigationService.Navigate(typeof(Views.QueryPage));
break;
default:
break;
}
}
else
{
NavigationService.Navigate(typeof(Views.CompaniesPage));
await Task.Yield();
}
}