Firebase Auth systems stopped working after signOut

Question

I was making a profile page. I also added a "Logout" button to the profile page.

The codes are as follows:

  InkWell(
    child: ListView(
      shrinkWrap: true,
      children: [
        ListTile(
          leading: Icon(Icons.person, color: Colors.black,),
          title: Text("Profile", style: TextStyle(fontSize: 20, fontWeight: FontWeight.bold, color: Colors.black),),
          onTap: () {
            //Navigator.push(context, MaterialPageRoute(builder: (context) => profileScreen()));
          },
        ),
        ListTile(
          leading: Icon(Icons.settings, color: Colors.black,),
          title: Text("Settings", style: TextStyle(fontSize: 20, fontWeight: FontWeight.bold, color: Colors.black),),
          onTap: () {
            //Navigator.push(context, MaterialPageRoute(builder: (context) => settingsScreen()));
          },
        ),
        ListTile(
          leading: Icon(Icons.exit_to_app, color: Colors.black,),
          title: Text("Logout", style: TextStyle(fontSize: 20, fontWeight: FontWeight.bold, color: Colors.black),),
          onTap: () {
            FirebaseAuth.instance.signOut(); // !!!!!!!!!!!!<<<<<<<
          },
        ),
      ],
    ),
    onTap: () {
      print("clicked");
    },
  ),

Console:

W/System  (31904): Ignoring header X-Firebase-Locale because its value was null.

When I press the ListTile with "Logout" written FirebaseAuth.instance.signOut(); the code would work. I pressed it and my access to the account was cut off. It also gave a few errors but those errors were normal errors anyway.

Then I tried to login to the account again, I couldn't. It gave an error other than password and email errors.

Apart from these, functions such as registration and forgot password do not work.

What could have caused this problem? How can I solve it? Thanks in advance for your help.