Firebase google auth does not sign out completely

Using the very clear simple examples provided by Google (Firebase Google Auth)I have been unable to log out from google.

Everytime sign I call this method using a button, it allows me to log in and navigates me to the local host.

function logGoogle() {

firebase.auth().signInWithPopup(provider).then(function(result) {
  // This gives you a Google Access Token. You can use it to access the Google API.
  var token = result.credential.accessToken;
  // The signed-in user info.
  var user = result.user;
  location.href = 'http://localhost:8080';
  // ...
}).catch(function(error) {
  // Handle Errors here.
  var errorCode = error.code;
  var errorMessage = error.message;
  // The email of the user's account used.
  var email = error.email;
  // The firebase.auth.AuthCredential type that was used.
  var credential = error.credential;
  // ...

  console.log(errorCode);
  console.log(errorMessage);
  console.log(email);
  console.log(credential);
});

}

however when i go back to the main menu which consists a log out button. It logs the session out, doesnt delete the session. When i log back in, i do not need to enter google cre

function logOutGoogle() {
  firebase.auth().signOut().then(function () {
    console.log("you logged off");

   
 location.href = 'http://localhost/GoogleVue3/';
  }).catch(function (error) {
    alert(error);
  });
}

I tried in incognito mode. entered google creds, went to the app, and decided to log out. Click on to sign in google, it automatically takes me to the app.

any advices?