unity Firebase Facebook auth on Android

Question

Integrating facebook as an auth provider within firebase (already have a working gmail implementation). The below code works fine in Unity, the FB SDK prompts for token, enter it manually, token is passed to firebase, login can be seen in the console, the required scene is then loaded.

When this is built onto an android device the full behavior doesnt happen, the correct Facebook token is received either from fresh login or existing login, we enter the SignInWithFacebookOnFirebase function to log this account into firebase and nothing else happens, sits on the debug of ("your token is " + aToken);

Im pretty sure it has something to do with the async behaviour and maybe not awaiting the task but im not sure what, any suggestions would be great !

using System.Collections.Generic;
using UnityEngine;
using Facebook.Unity;
using TMPro;
using UnityEngine.SceneManagement;
using Firebase.Auth;
using Firebase;
    
    public class FacebookAuth : MonoBehaviour
    {
        private FirebaseAuth auth;
        public TMP_Text debug; 
       void Awake ()
    {
      if (FB.IsInitialized) {
        FB.ActivateApp();
      } else {
        //Handle FB.Init
        FB.Init( () => {
          FB.ActivateApp();
        });
      }
      
      CheckFirebaseDependencies();
    }
    
       private void CheckFirebaseDependencies()
        {
            FirebaseApp.CheckAndFixDependenciesAsync().ContinueWith(task =>
            {
                if (task.IsCompleted)
                {
                    if (task.Result == DependencyStatus.Available)
                        auth = FirebaseAuth.DefaultInstance;
                    else
                        debug.text =("Could not resolve all Firebase dependencies: " + task.Result.ToString());
                }
                else
                {
                    debug.text =("Dependency check was not completed. Error : " + task.Exception.Message);
                }
            });
        }
    
    void OnApplicationPause (bool pauseStatus)
    {
      // Check the pauseStatus to see if we are in the foreground
      // or background
      if (!pauseStatus) {
        //app resume
        if (FB.IsInitialized) {
          FB.ActivateApp();
        } else {
          //Handle FB.Init
          FB.Init( () => {
            FB.ActivateApp();
          });
        }
      }
    }
        private void InitCallBack()
        {
            if(!FB.IsInitialized)
            {
                FB.ActivateApp();
            }
            else
            {
              //  debug.text=("Failed to initialize");
            }
        }
        private void OnHideUnity(bool isgameshown)
        {
            if(!isgameshown)
            {
                Time.timeScale = 0;
            }
            else
            {
                Time.timeScale = 1;
            }
        }    
    
        public void Facebook_Login()
        {
            var permission = new List<string>() { "public_profile", "email" };
            if (!FB.IsLoggedIn)
            {
            FB.LogInWithReadPermissions(permission, AuthCallBack);
            }
            else
            {
              var aToken = AccessToken.CurrentAccessToken.TokenString;
              debug.text=("already logged in - starting game" + aToken);  
              //THIS IS THE PROBLEM ON ANDROID - ITS NOT HAPPENING/async issue? 
              SignInWithFacebookOnFirebase(aToken); 
              
              SceneManager.LoadScene(1);
            }
        }
    
        public void LogOut()
        {
          FB.LogOut(); 
           debug.text=("Logged out of facebook");
        }
    
    
    
            private void SignInWithFacebookOnFirebase(string idToken)
        {
          
            Firebase.Auth.Credential credential = Firebase.Auth.FacebookAuthProvider.GetCredential(idToken);
            auth.SignInWithCredentialAsync(credential).ContinueWith(task => {
              if (task.IsCanceled) {
                  Debug.LogError("SignInWithCredentialAsync was canceled.");
                  return;
              }
              if (task.Exception != null) {
                  Debug.LogWarning("SignInWithCredentialAsync encountered an error: " + task.Exception);
              
                FirebaseException firebaseEx = task.Exception.GetBaseException() as FirebaseException;
                AuthError errorCode = (AuthError)firebaseEx.ErrorCode;
                  string message = "Login Failed!";
                switch (errorCode)
                {
                    case AuthError.AccountExistsWithDifferentCredentials:
                        message = "Your account is already linked to an email address";
                        break;
                      //we can add other conditions here if required to catch exceptions 
                }
                debug.text=(message); 
              }
               else{
                            
    
              Firebase.Auth.FirebaseUser newUser = task.Result;
            
              Debug.LogFormat("User signed in successfully: {0} ({1})",
                  newUser.DisplayName, newUser.UserId);
                  debug.text=("Logged into facebook");  
                  
                
              }
               });
            
        }

    
        private void AuthCallBack(ILoginResult result)
        {
            if(FB.IsLoggedIn)
            {
                var aToken = result.AccessToken.TokenString;
                
                debug.text=("your token is " + aToken); 
                  //THIS IS THE PROBLEM ON ANDROID - ITS NOT HAPPENING/async issue? 
                SignInWithFacebookOnFirebase(aToken); 
                debug.text=("weve signed into firebase");
              
                SceneManager.LoadScene(1);
                
            }
            else
            {
                debug.text=("User Cancelled login");
            }
        }
    
    
    }

EDIT - So the problem is nothing to do with async, its the fact that the firebase credential is being persisted on the mobile device. I uncommented all of my already working google auth code below and we log into firebase with our facebook creds fine! So i need some method of clearing our this token when A) the user logs out and B) the user closes the app (Cleanly or uncleanly) Any help would be great !

 using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Threading.Tasks;
    using Firebase;
    using Firebase.Auth;
    using Google;
    using TMPro;
    using UnityEngine;
    using UnityEngine.SceneManagement;
    using UnityEngine.UI;
    
    public class GoogleAuth : MonoBehaviour
    {  /*
        public TMP_Text infoText;
        public string webClientId = "<your client id here>";
    
        private FirebaseAuth auth;
        private GoogleSignInConfiguration configuration;
    
        private void Awake()
        {
            configuration = new GoogleSignInConfiguration { WebClientId = webClientId, RequestEmail = true, RequestIdToken = true };
            CheckFirebaseDependencies();
        }
    
        private void CheckFirebaseDependencies()
        {
            FirebaseApp.CheckAndFixDependenciesAsync().ContinueWith(task =>
            {
                if (task.IsCompleted)
                {
                    if (task.Result == DependencyStatus.Available)
                        auth = FirebaseAuth.DefaultInstance;
                    else
                        AddToInformation("Could not resolve all Firebase dependencies: " + task.Result.ToString());
                }
                else
                {
                    AddToInformation("Dependency check was not completed. Error : " + task.Exception.Message);
                }
            });
        }
    
        public void SignInWithGoogle() { OnSignIn(); }
        public void SignOutFromGoogle() { OnSignOut(); }
    
        private void OnSignIn()
        {
            GoogleSignIn.Configuration = configuration;
            GoogleSignIn.Configuration.UseGameSignIn = false;
            GoogleSignIn.Configuration.RequestIdToken = true;
            AddToInformation("Calling SignIn");
    
            GoogleSignIn.DefaultInstance.SignIn().ContinueWith(OnAuthenticationFinished);
            
        }
    
        private void OnSignOut()
        {
            AddToInformation("Calling SignOut");
            GoogleSignIn.DefaultInstance.SignOut();
            
        }
    
        public void OnDisconnect()
        {
            
            GoogleSignIn.DefaultInstance.Disconnect();
            infoText.text=("signed out");
        }
    
        internal void OnAuthenticationFinished(Task<GoogleSignInUser> task)
        {
            if (task.IsFaulted)
            {
                using (IEnumerator<Exception> enumerator = task.Exception.InnerExceptions.GetEnumerator())
                {
                    if (enumerator.MoveNext())
                    {
                        GoogleSignIn.SignInException error = (GoogleSignIn.SignInException)enumerator.Current;
                        AddToInformation("Got Error: " + error.Status + " " + error.Message);
                    }
                    else
                    {
                        AddToInformation("Got Unexpected Exception?!?" + task.Exception);
                    }
                }
            }
            else if (task.IsCanceled)
            {
                AddToInformation("Cancelled");
            }
            else
            {
                AddToInformation("Welcome: " + task.Result.DisplayName + "!");
                AddToInformation("Email = " + task.Result.Email);
                //AddToInformation("Google ID Token = " + task.Result.IdToken);
                AddToInformation("Email = " + task.Result.Email);
                SignInWithGoogleOnFirebase(task.Result.IdToken);
                
            }
        }
    
        private void SignInWithGoogleOnFirebase(string idToken)
        {
            Credential credential = GoogleAuthProvider.GetCredential(idToken, null);
    
            auth.SignInWithCredentialAsync(credential).ContinueWith(task =>
            {
                AggregateException ex = task.Exception;
                if (ex != null)
                {
                    if (ex.InnerExceptions[0] is FirebaseException inner && (inner.ErrorCode != 0))
                        AddToInformation("\nError code = " + inner.ErrorCode + " Message = " + inner.Message);
                }
                else
                {
                    AddToInformation("Sign In Successful.");
                    SceneManager.LoadScene(1);
                }
            });
        }
    
        public void OnSignInSilently()
        {
            GoogleSignIn.Configuration = configuration;
            GoogleSignIn.Configuration.UseGameSignIn = false;
            GoogleSignIn.Configuration.RequestIdToken = true;
            AddToInformation("Calling SignIn Silently");
    
            GoogleSignIn.DefaultInstance.SignInSilently().ContinueWith(OnAuthenticationFinished);
        }
    
        public void OnGamesSignIn()
        {
            GoogleSignIn.Configuration = configuration;
            GoogleSignIn.Configuration.UseGameSignIn = true;
            GoogleSignIn.Configuration.RequestIdToken = false;
    
            AddToInformation("Calling Games SignIn");
    
            GoogleSignIn.DefaultInstance.SignIn().ContinueWith(OnAuthenticationFinished);
        }
    
        private void AddToInformation(string str) { infoText.text += "\n" + str; } */
    }

Answer 1

this is solved, it was because i was checking that the firebase dependences existed in both these scripts and it was throwing an exception. I found this using the logcat logs \adb logcat -s Unity ActivityManager PackageManager dalvikvm DEBUG