Why are messages not displayed in my chat application?

Question

For some reason, in the chat application that I do (using the video tutorial on youtube), messages are not displayed after sending, although they appear in Firebase Database log. Could you please tell me the reason for this? I really do not understand. Thanks you in advance.

Main code:

package Karasik.com;

import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.RelativeLayout;
import android.widget.TextView;
import com.firebase.ui.auth.AuthUI;
import com.firebase.ui.database.FirebaseListAdapter;
import com.firebase.ui.database.FirebaseListOptions;
import com.google.android.material.floatingactionbutton.FloatingActionButton;
import com.google.android.material.snackbar.Snackbar;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.database.FirebaseDatabase;
import android.text.format.DateFormat;

public class MainActivity extends AppCompatActivity {

private static int SIGN_IN_CODE=1;
private RelativeLayout activity_main;
private FirebaseListAdapter<Message> adapter;
private FloatingActionButton sendBtn;

    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if(requestCode==SIGN_IN_CODE) {
           if(requestCode == RESULT_OK) {
               Snackbar.make(activity_main, "You are authorized", Snackbar.LENGTH_LONG).show();
               displayAllMessages();
               } else {
                 Snackbar.make(activity_main, "You are not authorized", Snackbar.LENGTH_LONG).show();
                 finish();
           }
        }
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        activity_main=findViewById(R.id.activity_main);
        sendBtn = findViewById(R.id.btnSend);
        sendBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                EditText textField = findViewById(R.id.messageField);
                if(textField.getText().toString().equals(""))
                    return;
                FirebaseDatabase.getInstance().getReference().push().setValue(new Message(FirebaseAuth.getInstance().getCurrentUser().getEmail(), textField.getText().toString()));
                textField.setText("");
            }
        });

        //Пользователь ещё не авторизован
        if (FirebaseAuth.getInstance().getCurrentUser()==null)
            startActivityForResult(AuthUI.getInstance().createSignInIntentBuilder().build(), SIGN_IN_CODE);
        //Пользователь авторизован
        else {
            Snackbar.make(activity_main, "You are authorized", Snackbar.LENGTH_LONG).show();
            displayAllMessages();
        }
    }

    private void displayAllMessages() {
        ListView listOfMessages = findViewById(R.id.list_of_messages);
        FirebaseListOptions<Message> options =
                new FirebaseListOptions.Builder<Message>()
                        .setQuery(FirebaseDatabase.getInstance().getReference(), Message.class)
                        .setLayout(R.layout.list_item)
                        .build();
        adapter = new FirebaseListAdapter<Message>(options){
            @Override
            protected void populateView(View v, Message model, int position) {
                TextView mess_user, mess_time, mess_text;
                mess_user = v.findViewById(R.id.message_user);
                mess_time = v.findViewById(R.id.message_time);
                mess_text = v.findViewById(R.id.message_text);

                mess_user.setText(model.getUserName());
                mess_text.setText(model.getTextMessage());
                mess_time.setText(DateFormat.format("dd-MM-yyyy HH:mm:ss", model.getMessageTime()));
            }
        };
        listOfMessages.setAdapter(adapter);
    }
}

Class Message:

package Karasik.com;

import java.util.Date;

public class Message {
    private String UserName;
    private String TextMessage;
    private long MessageTime;

    public Message() {}
    public Message (String UserName, String TextMessage){
        this.UserName = UserName;
        this.TextMessage = TextMessage;

        this.MessageTime = new Date().getTime();
    }

    public String getUserName() {
        return UserName;
    }

    public void setUserName(String userName) {
        UserName = userName;
    }

    public String getTextMessage() {
        return TextMessage;
    }

    public void setTextMessage(String textMessage) {
        TextMessage = textMessage;
    }

    public long getMessageTime() {
        return MessageTime;
    }

    public void setMessageTime(long messageTime) {
        MessageTime = messageTime;
    }
}

Run log: