Why the system does not allow to delete the user?

Question

symfony

I'm trying to delete a user in symphony

if($userOriginal === $userDoubleCheck){
            $entityManager = $this->getDoctrine()->getManager();
            $entityManager->remove($userDoubleCheck);
            $entityManager->flush();

The system throws the error
You cannot refresh a user from the EntityUserProvider that does not contain an identifier. The user object has to be serialized with its own identifier mapped by Doctrine.
But in the user class I have id serialization

/** @see \Serializable::serialize() */
    public function serialize()
    {
        return serialize(array(
            $this->id,
            $this->username,
            $this->password,
//            $this->roles,
            // see section on salt below
            // $this->salt,
        ));
    }

    /** @see \Serializable::unserialize() */
    public function unserialize($serialized)
    {
        list (
            $this->id,
            $this->username,
            $this->password,
//            $this->roles,
            // see section on salt below
            // $this->salt
            ) = unserialize($serialized, array('allowed_classes' => false));
    }

those. how would I pass the id. I don't understand why she still swears at me.