FOS Rest Bundle - Controller must return Response object, but it returns View

I'm trying to setup FOS Rest Bundle on symfony 4.2.3. and I'm following this tutorial:

https://www.thinktocode.com/2018/03/26/symfony-4-rest-api-part-1-fosrestbundle/

Installed and configured the bundle:

//annotations.yaml
rest_controller:
    resource: ../../src/Controller/Rest/
    type: annotation
    prefix: /api

//fos_rest.yaml
fos_rest:
  view:
    view_response_listener:  true
  format_listener:
    rules:
      - { path: ^/api, prefer_extension: true, fallback_format: json, priorities: [ json ] }

and when I call postAction() of my ArticleController object, which looks like:

class ArticleController extends FOSRestController
{
/**
 * Creates an Article resource
 * @Rest\Post("/articles")
 * @param Request $request
 * @return View
 */
public function postArticle(Request $request): View
{
    $entityManager = $this->getDoctrine()->getManager();

    $article = new Article();

    $article->setTitle($request->get('title'));
    $article->setContent($request->get('content'));


    $articleCategory = $entityManager->getReference(ArticleCategory::class, $request->get('article_category'));
    $article->setArticleCategory($articleCategory);

    $article->setPublished($request->get('published'));

    $entityManager->persist($article);
    $entityManager->flush();

    // In case our POST was a success we need to return a 201 HTTP CREATED response
    return View::create($article, Response::HTTP_CREATED);
}

}

I get the error message (testing with Postman): The controller must return a "Symfony\Component\HttpFoundation\Response" object but it returned an object of type FOS\RestBundle\View\View.

Why is that?! It's defined that postArticle() method should return a View object and I'm doing that.

One notice: my class is extending FOSRestController class, which is deprecated. I also tried extending AbstractFOSRestController, but with the same result.