Symfony multiple image uploader doesn't work when uploading one by one

I'm trying to set up a form with a FileType field with the multiple option enabled, but if I upload one by one, when submited it only sends the last one to the controller.
I would like to send every file that has been added to the input when submitted. Is there any way to send them?

My form field

class AnadirBarcoFotosForm extends AbstractType
{
    public function buildForm(FormBuilderInterface $builder, array $options)
    {   
        $builder              
        ->add('imagenes', FileType::class,[
            'label' => false,
            'multiple' => true,
            'required' => false
        ])
        ->add('Guardar', SubmitType::class, [
            'attr'  =>  [
                'class' => 'btn btn-secondary float-right boton-marron'
            ]
        ])
        ;
    }
   
    public function configureOptions(OptionsResolver $resolver)
    {
        $resolver->setDefaults([

        ]);
    }
}

Controller

$paramAnadirBarcoFotos = array();
$anadirBarcoFotosForm = $this->createForm(AnadirBarcoFotosForm::class, $paramAnadirBarcoFotos);
$anadirBarcoFotosForm->handleRequest($request);

if ($anadirBarcoFotosForm->isSubmitted() && $anadirBarcoFotosForm->isValid()){
    $datosAnadirBarcoFotos = $anadirBarcoFotosForm->getData();
...