Symfony Embedded Form Validation

I have several Entities, that are used in a single form, that extends from an abstract class. I have created a form type for each entity and then they were embedded in a parent form.

I would like to perform validation based on groups, so the EmailType must check the "elemento" property only on Assert\NotBlank (Default group) and Assert\Email (email group), and Telefono must check Assert\NotBlank (Default group) and Assert\Regex (phone group).

With my configuration both checks (constraints) are performed, so email are checked on Email constraint AND Regex, and so the phone filed is... Where am i wrong?

Staff Entity on Collection emails and phones have configured the Assert\Valid() contraint

This is the example

Parent Form

<?php
namespace App\Form\Staff;

class StaffType extends AbstractType {

     public function configureOptions(OptionsResolver $resolver) {
           $resolver->setDefaults(['data_class' => \Cowbell\Entity\Staff\Staff::class,
                     'validation_groups' => ['Default', 'email', 'phone']]);
}
    /**
     * 
     * @param FormBuilderInterface $builder
     * @param array $options
     */
    public function buildForm(FormBuilderInterface $builder, array $options) {


        // ... Other field of Staff Entity

        ->add('emails', CollectionType::class, ['label' => 'admin.emails',
                'entry_type' => \App\Form\Contatto\CBEmailType::class,
                'entry_options' => ['label' => false],
                'allow_add' => true,
                'allow_delete' => true,
                'empty_data' => null,
                'translation_domain' => 'admin',
                'validation_groups' => ['email']])
            ->add('telefoni', CollectionType::class, ['label' => 'admin.phones',
                'entry_type' => \App\Form\Contatto\CBTelefonoType::class,
                'entry_options' => ['label' => false],
                'allow_add' => true,
                'allow_delete' => true,
                'empty_data' => null,
                'translation_domain' => 'admin',
                'validation_groups' => ['phone']]);

    }

}

Then CBEmailType

<?php
namespace App\Form\Contatto;

class CBEmailType extends AbstractType{

    /**
     * 
     * @param OptionsResolver $resolver
     */
    public function configureOptions( OptionsResolver $resolver)
    {
        $resolver->setDefaults(['data_class' => \App\Entity\Contatto\Email::class,
        'validation_groups' => ['Default', 'email']]);;
    }

    public function buildForm(FormBuilderInterface $builder, array $options) {

        $builder->add('elemento', EmailType::class, ['label' => 'admin.email',
                  'translation_domain' => 'admin'])

    }

}

CBTelefonoType

<?php
namespace App\Form\Contatto;

class CBTelefonoType extends AbstractType{

    /**
     * 
     * @param OptionsResolver $resolver
     */
    public function configureOptions( OptionsResolver $resolver)
    {
        $resolver->setDefaults(['data_class' => \Cowbell\Entity\Contatto\Telefono::class,
        'validation_groups' => ['Default', 'phone']]);
    }

    public function buildForm(FormBuilderInterface $builder, array $options) {

        $builder->add('elemento', TextType::class, ['label' => 'admin.phone',
                'translation_domain' => 'admin'])

    }

}

Both, Email and Telefono extend

<?php
namespace App\Entity\Contact;

use Doctrine\ORM\Mapping as ORM;
use Symfony\Component\Validator\Constraints as Assert;

abstract class AbstractElementoContact {


    /**
     * 
     * @var string
     *
     * @ORM\Column(name="elemento", type="string", length=100, nullable=false)
     * @Assert\NotBlank()
     * @Assert\Email(strict=true, checkHost=true, checkMX=true, groups={"email"})
     * @Assert\Regex("/[0-9]{6,50}/", groups={"phone"})
     */
    protected $elemento;