Symfony EasyAdminBundle event pre_update triggered twice - symfony

Question

I've created an event subscriber that sends an email with Swiftmailer every time certain entity is updated but the event is triggered twice so i'm receiving email two times.
I've followed this guide and this one. The event is: easy_admin.pre_update
EasyAdminBundle version: 1.17.9
services.yml
app.easy_admin.aprobar_publicacion:
class: AppBundle\EventListener\AprobarPublicacionSubscriber
arguments: ['#mailer','#service_container','#twig']
tags:
- { name: kernel.event_subscriber, event: easy_admin.pre_update, method: preUpdate }
AprobarPublicacionSubscriber.php
<?php
namespace AppBundle\EventListener;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;
use Symfony\Component\EventDispatcher\GenericEvent;
use AppBundle\Entity\VestidoDeNovia;
use AppBundle\Entity\PlantillaEmail;
class AprobarPublicacionSubscriber implements EventSubscriberInterface {
protected $mailer;
protected $container;
protected $twig;
public static function getSubscribedEvents() {
return array(
'easy_admin.pre_update' => array('preUpdate'),
);
}
public function __construct(\Swift_Mailer $mailer, \Symfony\Component\DependencyInjection\ContainerInterface $container, \Twig_Environment $twig) {
$this->mailer = $mailer;
$this->container = $container;
$this->twig = $twig;
}
public function preUpdate(GenericEvent $event) {
$entity = $event->getSubject();
if (!($entity instanceof VestidoDeNovia)) {
return;
}
$uow = $event->getArgument('em')->getUnitOfWork();
$uow->computeChangeSets();
$changeset = $uow->getEntityChangeSet($entity);
if (array_key_exists('estado', $changeset)) {
$estadoActual = $changeset['estado'][0]->getId();
if ($estadoActual != 2 and $entity->getEstado()->getId() == 2) {
$plantillaEmail = new PlantillaEmail();
$plantillaEmail = $event->getArgument('em')->getRepository(PlantillaEmail::class)->find(6);
$message = (new \Swift_Message($plantillaEmail->getAsunto()))
->setFrom($this->container->getParameter('direccion_mail_sistema'))
->setTo($entity->getUsuario()->getEmail())
->setBody(
$this->twig->render(
'AppBundle::Emails/publicacion_exitosa.html.twig', array(
'titulo' => $plantillaEmail->getAsunto(),
'mensaje' => $plantillaEmail->getMensaje(),
)
), 'text/html'
)
;
$this->mailer->send($message);
}
}
}
}
What am i missing?