[REQUIRED] Please fill in the following fields:

• Unity editor version: 2021.3.16
• Firebase Unity SDK version: 9.6.0
• Source you installed the SDK: .unitypackage
• Problematic Firebase Component: Auth
• Other Firebase Components in use: Database
• Additional SDKs you are using: Facebook, Admob, Bugsee
• Platform you are using the Unity editor on: Mac
• Platform you are targeting: IOS
• Scripting Runtime: IL2CPP

[REQUIRED] Please describe the issue here:

I have two Login Options.
1: Login with Google
2: Login as Guest

I am following this
https://firebase.google.com/docs/auth/unity/anonymous-auth
for login as anonymously.
On login success It creates a unique user ID (That's a correct behaviour).
But when I Logout using
auth.SignOut(); (firebase Auth method).

and then for a reason I want to login as guest again It creates new user ID all the way.
Is there anyway to get my old Authenticated data (with old USERID). Because based on this user ID I am saving some data in firebase database.
Assigning new userid always is not good for my game requirements.

Login with Google (use firebase) is good. It always return FirebaseUser with same USERID.