Why the app doesn't change to the language I already saved after close

Question

I have some issues with changing the language in the app. I do not know why it is not working, there is no error, checked the log all clear.

I used the following code in the splash screen. It worked well in the beginning, but after I added admob ads, it no longer works,. Only the first page is translated and then it's back to the language of the system after I reload the page.

import androidx.appcompat.app.AppCompatActivity;

import android.app.Activity;
import android.app.ActivityOptions;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.res.Configuration;
import android.content.res.Resources;
import android.os.Bundle;
import android.os.Handler;
import android.util.DisplayMetrics;
import android.view.View;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;

import java.util.Locale;

public class MainActivity extends AppCompatActivity {

    private final int SPLASH_DISPLAY_LENGTH = 2500;

    ImageView imagesplash;
    SharedPreferences prefs;

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

        imagesplash =  findViewById(R.id.logosplash);
        Animation hyperspaceJump = AnimationUtils.loadAnimation(this, R.anim.animsplashscreen);
        imagesplash.startAnimation(hyperspaceJump);
        //lang
        prefs= MainActivity.this.getSharedPreferences("Settings", Activity.MODE_PRIVATE);
        String  Language = prefs.getString("lang", Locale.getDefault().getLanguage().trim());

if (Language.equals(""))
{
    LoadLanguage("en");
    Intent o = getBaseContext().getPackageManager().getLaunchIntentForPackage(getBaseContext().getPackageName());
    o.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
    startActivity(o);

}

        //splash
        new Handler().postDelayed(new Runnable(){
            @Override
            public void run() {

                      Intent intt = new Intent(MainActivity.this, Startpage.class);
                ActivityOptions options =
                        ActivityOptions.makeCustomAnimation(MainActivity.this, R.anim.slid_in_left, R.anim.slid_out_right);
                startActivity(intt, options.toBundle());

                finish();

            }
        },SPLASH_DISPLAY_LENGTH);




    }

    public void onBackPressed() {

    }
    public void LoadLanguage(String lang){


        Locale locale2 = new Locale(lang);
        Locale.setDefault(locale2);
        Configuration config2 = new Configuration();
        config2.locale = locale2;
        getBaseContext().getResources().updateConfiguration(config2, getBaseContext().getResources().getDisplayMetrics());



    }

}