Doctrine oneToOne self-referencing delete foreign key

I have some issue deleting a foreign key from a self-referencing entity. I would like to remove an entity and delete its reference (feature_group_parent_id) from any other entities.

/**
 * @Entity
 * @Table(name="ps_biotexconfigurator_feature_groups")
 */
class ConfFeatureGroup
{
   /**
    * @var string
    *
    * @Id
    * @Column(type="string")
    * @GeneratedValue(strategy="NONE")
    */
   private $id_biotexconfigurator_feature_group;

   /**
    * @var int
    *
    * @Column(type="integer")
    */
   private $feature_id;

   /**
    * @var string
    *
    * @Column(type="string", nullable=true)
    */
   private $feature_group_parent_id;

   /**
    * @var ConfFeatureGroup 
    *
    * @OneToOne(targetEntity="BiotexConfigurator\Entity\ConfFeatureGroup")
    * @JoinColumn(name="feature_group_parent_id", referencedColumnName="id_biotexconfigurator_feature_group", onDelete="SET NULL")
    */
   private $feature_group_parent;



   // Other fields ...

}

I am using the version included in Prestashop 1.7.8, which should be v2.6. As you can see, I have already tried with onDelete="SET NULL" but it does not work, here is the error message:

Uncaught PHP Exception Doctrine\DBAL\Exception\ForeignKeyConstraintViolationException: "An exception occurred while executing 'DELETE FROM ps_biotexconfigurator_feature_groups WHERE id_biotexconfigurator_feature_group = ?' with params ["234b3aba-36ee-4ff8-a497-ad54beceb86d"]: SQLSTATE[23000]: Integrity constraint violation: 1451 Cannot delete or update a parent row: a foreign key constraint fails (`prestashop`.`ps_biotexconfigurator_feature_groups`, CONSTRAINT `ps_biotexconfigurator_feature_groups_ibfk_1` FOREIGN KEY (`feature_group_parent_id`) REFERENCES `ps_biotexconfigurator_feature_)" at /var/www/html/vendor/doctrine/dbal/lib/Doctrine/DBAL/Driver/AbstractMySQLDriver.php line 49

Is there a way to do it without writing a raw query before?