如何读取带有doctrine和symfony的DC2Type数组

I'm setting up an advanced search for a jobboard and I need to find resumes by contract, knowing that a resume can have multiple contracts.

I have a form where you can choose which type of contract you are looking for (It's a ChoiceType::class with multiple => true)

In my table, my colomn contract :

In my Entity Resume :

/**
 * @ORM\Column(type="array", nullable=true)
 */
private $contract = [];

public function getContract(): ?array
{
    return $this->contract;
}

public function setContract(?array $contract): self
{
    $this->contract = $contract;

    return $this;
}

In my repository :

public function findByContract(array $contract)
{
    return $this->createQueryBuilder('r')
        ->andWhere('r.contract IN (:cons)')
        ->setParameter('cons', $contract)
        ->getQuery()
        ->getResult()
    ;
}

In my controller :

public function index(Request $request, ResumeRepository $resumeRepository)
{
    $formSearch = $this->createForm(ResumeSearchFormType::class);
    $formSearch->handleRequest($request);

    if ($formSearch->isSubmitted() && $formSearch->isValid()) {
        $data = $formSearch->getData();

        $results = $resumeRepository->findByContract($data->getContract());
        var_dump($results); die;

This var_dump() returns an empty array.

I don't know how I can do to find resume by contract