Cannot navigate to page which was called once before - xamarin

Question

Short intro into my application's-logic:
My application is using a REST-Api and needs a token for all requests but a specific one (let's call it "pairing-page").
Before I navigate to any of my pages I'm checking the target location. If my target is the page where I'm requesting the token, no checking for a existing token is made.
For every other page a token is necessary. If no token exists the user should navigate back to the "pairing-page".
My start-Page is my paring-page.
What's the problem?:
When starting the app (pairing-page) and getting the token and navigating to the 2nd page - let's call it "overview" - everything is ok. The overview has a button which calls a method that removes my token and navigates back to the pairing-page. That's working as well.
Now the interesting part:
When I try to pair & navigate to the overview again (2nd time), no navigation is done. By this I mean my overview is not popping up.
I'm using Xamarin's Shell Navigation and overriding the OnNavigating-Method.
Code:
protected override void OnNavigating(ShellNavigatingEventArgs args)
{
// check if BearerToken exist. If so, navigate to Overview
if (args.Target.Location.ToString() != "//Admission.Event.Pair"
&& args.Target.Location.ToString() != "Admission.Event.Pair")
{
App app = App.Current as App;
string bearerToken = RestServiceCalls.GetBearerToken(app._dependencyService);
// if a the token is missing call the Pairing-Page
if (string.IsNullOrEmpty(bearerToken)
|| string.IsNullOrWhiteSpace(bearerToken))
{
Device.BeginInvokeOnMainThread(async () => { await NavigateToPageAsync("Admission.Event.Pair"); });
return;
}
}
base.OnNavigating(args);
}
async Task NavigateToPageAsync(object pageName, bool animate = true)
{
await Xamarin.Forms.Shell.Current.GoToAsync($"{pageName.ToString()}", animate);
Xamarin.Forms.Shell.Current.FlyoutIsPresented = false;
}
Let's take a look into the args:
Application start, pairing-page:
args.Target.Location: //Admission.Event.Pair
args.Current.Location: null
The Pairing-Page is popping up, everything is ok.
Click on the Button which processes getting a token and after that navigating to the overview:
args.Target.Location: Admission.Event
args.Current.Location: //Admission.Event.Pair
The overview page is popping up, everything is ok. Got a valid token as well.
Click on Button which processes removing the token and navigating to the pairing-page:
args.Target.Location: Admission.Event.Pair
args.Current.Location: //Admission.Event.Pair/Admission.Event
The token is removed correctly (is null) and the pairing-page pops up. Everything is ok.
Now the problem occurs:
When I'm now trying to get a token and navigate to the overview again my args have this content and my overview wont show up:
args.Target.Location: Admission.Event
args.Current.Location: //Admission.Event.Pair/Admission.Event/Admission.Event.Pair
Any idea about that?
My first thought was it might be an issue with the target-location.

Answer 1

Like I said in my comment:
For me I could simple use:
if(shell != null){
INavigation navigation = shell.Navigation;
navigation.PopToRootAsync();
}