Doctrine query result is empty but the generated running query works in Postgres

Question

I have a native query in Doctrine, which generate the right SQL, which runs in PostgreSQL. However the Doctrine returns null/empty results.

public count unReadedNotifications(User $user) {

    $rsm = new ResultSetMapping();

    $sql =
        "SELECT count(ele->'status') FROM notification CROSS JOIN LATERAL jsonb_array_elements(items) status(ele) WHERE notification.id = ? and (ele->'status')::jsonb @> '1'";

    $query = $this->getEntityManager()->createNativeQuery($sql,$rsm)->setParameter('1', $user->getNotification()->getId());
    return $query->getSingleScalarResult();
}

This Doctrine native query returns null. If I check the profiler I see the generated query is:

SELECT count(ele->'status') FROM notification CROSS JOIN LATERAL jsonb_array_elements(items) status(ele) WHERE notification.id = 21 and (ele->'status')::jsonb @> '1';

If I copy-paste this into pgAdmin it runs and it retrieve the desired "2".

So pgAdmin can gives me the right result, but Doctrine not.

Can somebody see, where and what went wrong?

Doctrine version: 2.6.3, Postgres is 10.