Can't connect to MS SQL Server via another WiFi; java.sqlSQLException: Network error IOException: Host unreachable

Question

I've made a SQL Server and managed to form a database. Implemented everything in my Android Studio app and opened the app on my phone.

When I access the database from the same WiFi network where the database is formed, everything works, but when I access the database from another WiFi network I get the exception:

java.sql.SQLException: Network error IOException: Host unreachable

Can you make the server accessible from every other network apart from the network that the database is connected to? Or do I have to do something else to make it accessible from everywhere?

Things I've already done:

• Every SQL services are up and running.
• Shared Memory, Named Pipes and TCP/IP are enabled.
• Remote server connections is Allowed on my database.
• New account is created (I don't use the sa account).
• I've made an exception in the firewall for the port (1433).

I will add the code from my app if that helps in any way.

import android.Manifest;
import android.content.Intent;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;

import android.content.pm.PackageManager;
import android.os.Bundle;
import android.os.StrictMode;
import android.view.View;
import android.view.Window;
import android.widget.TextView;
import android.widget.Toast;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class MainActivity extends AppCompatActivity {
    TextView moreGames;
    String b;
    private static String ip = "xxx.xxx.x.x";
    private static String port = "1433";
    private static String Classes = "net.sourceforge.jtds.jdbc.Driver";
    private static String database = "xxxx";
    private static String username = "xxxxxx";
    private static String password = "xxxx";
    private static String url = "jdbc:jtds:sqlserver://" + ip + ":" + port + "/" + database;
    private Connection connection = null;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.activity_main);
        moreGames = findViewById(R.id.moreGames);
        ActivityCompat.requestPermissions(this, new String[]{(Manifest.permission.INTERNET)}, PackageManager.PERMISSION_GRANTED);
        StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
        StrictMode.setThreadPolicy(policy);
        try {
            Class.forName(Classes);
            connection = DriverManager.getConnection(url, username, password);
            moreGames.setText(R.string.NewGame);
        } catch (ClassNotFoundException e){
            e.printStackTrace();
            Toast.makeText(this, "Error somewhere.", Toast.LENGTH_SHORT).show();
        } catch (SQLException e){
            b = String.valueOf(e);
            Toast.makeText(this, b, Toast.LENGTH_LONG).show();
        }