Doctriny - Symfony Flush not adding to DataBase - symfony

Question

The flush function does not add anything to the database even though it doesn't return any error.
Any idea of how can I solve that?
Thanks in advance for your help!
Here is my code:
Controller:
#[Route("/messages")]
public function create(Request $request, ManagerRegistry $signup, UserRepository $userRepository, MessageRepository $messageRepository): Response
{
$message = new Message();
$userRepository = $signup->getRepository(User::class);
$formdico = [];
foreach ($userRepository->findAll() as $user) {
$userform = $this->createForm(MessageType::class, $message);
$formdico[$user->getId()] = $userform;
}
foreach ($formdico as $form) {
$form->handleRequest($request);
if ($form->isSubmitted() && $form->isValid()) {
$newMessage = new Message();
$newMessage->setSender($userRepository->findOneById($form->getData()->getSender()));
$newMessage->setReceiver($userRepository->findOneById($form->getData()->getSender()));
$newMessage->setContent($form->getData()->getContent());
$newMessage->setCreatedAt(new \DateTime('now'));
$em = $signup->getManager();
$em->persist($newMessage);
$em->flush($newMessage);
}
}
foreach ($userRepository->findAll() as $user) {
$userform = $this->createForm(MessageType::class, $message);
$formdico[$user->getId()] = $userform->createView();
}
return $this->render('message/readAllUser.html.twig', ['users' => $userRepository->findAll(), "formdico" => $formdico, 'messages' => $messageRepository->findAll()]);
}
Entity:
<?php
namespace App\Entity;
use Doctrine\ORM\Mapping as ORM;
#[ORM\Entity()]
class Message
{
#[ORM\Id]
#[ORM\GeneratedValue(strategy: "AUTO")]
#[ORM\Column(type: "integer")]
private int $id;
#[ORM\ManyToOne(targetEntity: "App\Entity\User", inversedBy: "sendedMessages")]
private $sender;
#[ORM\ManyToOne(targetEntity: "App\Entity\User", inversedBy: "receivedMessages")]
private $receiver;
#[ORM\Column(type: "text")]
private string $content;
#[ORM\Column(type: "date")]
private \DateTime $createdAt;
/**
* Get the value of id
*/
public function getId()
{
return $this->id;
}
/**
* Set the value of id
*
* #return self
*/
public function setId($id)
{
$this->id = $id;
return $this;
}
/**
* Get the value of sender
*/
public function getSender()
{
return $this->sender;
}
/**
* Set the value of sender
*
* #return self
*/
public function setSender($sender)
{
$this->sender = $sender;
return $this;
}
/**
* Get the value of receiver
*/
public function getReceiver()
{
return $this->receiver;
}
/**
* Set the value of receiver
*
* #return self
*/
public function setReceiver($receiver)
{
$this->receiver = $receiver;
return $this;
}
/**
* Get the value of content
*/
public function getContent()
{
return $this->content;
}
/**
* Set the value of content
*
* #return self
*/
public function setContent($content)
{
$this->content = $content;
return $this;
}
/**
* Get the value of createdAt
*/
public function getCreatedAt()
{
return $this->createdAt;
}
/**
* Set the value of createdAt
*
* #return self
*/
public function setCreatedAt($createdAt)
{
$this->createdAt = $createdAt;
return $this;
}
}
Form:
<?php
namespace App\Form;
use App\Entity\Message;
use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\OptionsResolver\OptionsResolver;
use Symfony\Component\Form\Extension\Core\Type\TextType;
use Symfony\Component\Form\Extension\Core\Type\IntegerType;
class MessageType extends AbstractType
{
public function buildForm(FormBuilderInterface $builder, array $options): void
{
$builder
->add('sender', IntegerType::class, [])
->add('content', TextType::class, ['label' => false, 'attr' => ['placeholder' => 'Message Content']])
->add('receiver', IntegerType::class, []);
}
public function configureOptions(OptionsResolver $resolver): void
{
$resolver->setDefaults(['data_class' => Message::class,]);
}
}
I tried removing the persist, dumped a lot of things to try understanding the problem but I can't get to solve this...
And the form is valid