Driver fails to call PHP model

How about, I'm a bit green in this, I was creating an api with php following the mvc model, I had managed to connect to the base using PDO, I did my controller std, my users ctrl, user model and my index, it works well with only one (users), but the moment I create a second ctrl, the model stops working and prints only the call to the model.

This is the code

Index.php

if (!isset($_GET['ctrl'])){
        $_GET['ctrl'] = 'index';
    }
    switch($_GET['ctrl']){
        case 'index':
            echo "No hagas nada";
            break;
        case 'usuarios':
            // cargar el archivo de users controllers
            require_once('controllers/UsersController.php');
            // crear objeto
            $controller = new UsersController();
            break;
        case 'tutoriales':
            // cargar el archivo de users controllers
            require_once('controllers/TutorialsController.php');
            // crear objeto
            $controller = new TutorialsController();
            break;
        default:
            echo "El controlador seleccionado no es valido";
        $controller->ejecutar();'

Controller.php

    class Controller{
    public function __construct(){
    }
    public function ejecutar(){
      if (!isset($_GET['act']))
      {
        $_GET['act'] = 'read';
      }
      switch($_GET['act'])
      {
        case 'read':
          $this->read();
          break;
        case 'create':
          $this->create();
          break;
        case 'update':
          $this->update();
          break;
        case 'delete':
          $this->delete();
          break;
        default:
          echo 'Acción no reconocida';
      }
    }

    public function create(){
      echo json_encode($this->model->Create());
    }
    public function read(){
      //echo 'Este debe listar los productos';
      echo json_encode($this->model->Show());
    }
    public function update(){
      //echo 'Este debe listar los productos';
      echo json_encode($this->model->Update());
    }
    public function delete(){
      //echo 'Este debe listar los productos';
      echo json_encode($this->model->Delete());
    }

userController.php

require_once('Controller.php');

class UsersController extends Controller {

    public $model;

    public function __construct(){
      parent::__construct();

      require_once('./models/Users.php');

      private static $this->model = new Users();
    }

User.php (model)

include_once('c:/xampp/htdocs/ForoCucei/foro-cucei-api/Database.php');

class Users {

function __construct(){
  $this->connection = DataBase::connection();
}

//function SignUp($data){
  //return $this->db->insert('users', $data);
//  return $this->db->insert('users', $data);
//}
function Show(){
  $st = $this->pdo->prepare('SELECT * FROM users');
  $st->execute();
  $result = $st->fetchAll(PDO::FETCH_OBJ);
  return $result;
}
function Create(){
  $name = 'Tony';
  $last = 'Stark';
  $nick = 'Ironman';
  $mail = '[email protected]';
  $pass = '+Carlos1';
  $passHash = password_hash($pass, PASSWORD_BCRYPT);
  $st = $this->pdo->prepare('INSERT INTO users(name, last, nick, mail, pass) VALUES (:name, :last, :nick, :mail, :pass)');
  $st->bindValue(":name", $name);
  $st->bindValue(":last", $last);
  $st->bindValue(":nick", $nick);
  $st->bindValue(":mail", $mail);
  $st->bindValue(":pass", $passHash);
  $st->execute();
  $result = $st->fetchAll(PDO::FETCH_OBJ);
  return $result;
}
function Update(){
  $id = 2;
  $name = 'Kimi';
  $last = 'Raikkonen';
  $nick = 'iceman';
  $mail = '[email protected]';
  $st = $this->pdo->prepare('UPDATE users
    SET 'name' = :name,
        'last' = :last,
        'nick' = :nick,
        'mail' = :mail
    WHERE 'iduser' = :id
  ');
  $st->bindValue(":id", $id);
  $st->bindValue(":name", $name);
  $st->bindValue(":last", $last);
  $st->bindValue(":nick", $nick);
  $st->bindValue(":mail", $mail);
  $st->execute();
  $result = $st->fetchAll(PDO::FETCH_OBJ);
  return $result;
}
function Delete(){
  $id = 3;
  $st = $this->pdo->prepare('DELETE FROM users WHERE 'iduser' = :id');
  $st->bindValue(":id", $id);
  $st->execute();
  $result = $st->fetchAll(PDO::FETCH_OBJ);
  return $result;
}

}