shared preferences are deleted when you close and open app XC wtf

When I select the image it saves it well and I can open it in other activitys when I close and open the app and the image does not appear in any activity, the same thing happens to me with audio files that I put in other activites what am I doing wrong in the manifest I have permission

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

public class llamador extends AppCompatActivity {
    ImageView imagen;
    EditText edit_txt_1,edit_txt_2;
    Button btn_guardar;
    private static final int PICK_IMAGE = 100;
    public Uri imagenUri;
    public SharedPreferences prefs;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_llamador);
        setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
        Toolbar myToolbar = findViewById(R.id.my_toolbar);
        setSupportActionBar(myToolbar);
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
        getSupportActionBar().setDisplayShowHomeEnabled(true);
        myToolbar.setNavigationIcon(getResources().getDrawable(R.drawable.atras));
        myToolbar.setNavigationOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                finish();
            }
        });
        edit_txt_1=findViewById(R.id.remitente);
        edit_txt_2=findViewById(R.id.numero);
        btn_guardar=findViewById(R.id.hecho);
        imagen=findViewById(R.id.setimage);
        prefs = getSharedPreferences("MisPreferencias", this.MODE_PRIVATE);
        edit_txt_1.setText(prefs.getString("nombre","hermosa"));
        edit_txt_2.setText(prefs.getString("numero","desconocido"));
        imagenUri = Uri.parse(prefs.getString("imagenUri", null));
        imagen.setImageURI(imagenUri);

        imagen.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                showalertforcreatingboard();
            }
        });

        btn_guardar.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String nombre,numero;
                nombre=edit_txt_1.getText().toString();
                numero=edit_txt_2.getText().toString();
                shareonprefrence(numero,nombre);
                Intent j1=new Intent(llamador.this,MainActivity.class);
                startActivity(j1);
            }
        });
    }

    private void showalertforcreatingboard(){
        AlertDialog.Builder builder=new AlertDialog.Builder(this);
        View viewinflater= LayoutInflater.from(this).inflate(R.layout.imagen,null);
        builder.setView(viewinflater);

        final Button input2=viewinflater.findViewById(R.id.ponimagen);
        final Button input3=viewinflater.findViewById(R.id.quitaimagen);

        builder.setNegativeButton("cancel", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialogInterface, int i) {
            }
        });
        final AlertDialog dialog=builder.create();
        input2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                cam(view);
                dialog.dismiss();
            }
        });
        input3.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                imagen.setImageResource(R.drawable.user);
                Uri uriImage = Uri.parse("android.resource://" + getPackageName() +"/"+R.drawable.user);
                shareonprefrenceIma(uriImage);
                dialog.dismiss();
            }
        });
        dialog.show();
    }
    private void shareonprefrence(String numero,String nombre) {
        SharedPreferences.Editor editor = prefs.edit();
        editor.putString("numero", numero);
        editor.putString("nombre",nombre);
        editor.apply();
    }
    public void cam(View view) {
        Intent gallery = new Intent(Intent.ACTION_PICK, MediaStore.Images.Media.INTERNAL_CONTENT_URI);
        startActivityForResult(gallery, PICK_IMAGE);
    }
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data){
        if(resultCode == RESULT_OK && requestCode == PICK_IMAGE){
            imagenUri = data.getData();
            imagen.setImageURI(imagenUri);
            shareonprefrenceIma(imagenUri);
        }
    }
    private void shareonprefrenceIma(Uri imageUri) {
        SharedPreferences.Editor editor = prefs.edit();
        editor.putString("imagenUri", imageUri.toString());
        editor.apply();
    }
}