New developments concerning enum types are out now:

Doctrine DBAL 4.2 ships an Types::ENUM which should be preferred over implementing custom types for ENUM fields.

doctrine/orm#11666
doctrine/orm#11668

The following ways to use enums are yielding Property App\Entity\Project::$status: Doctrine type "enum" does not have any registered descriptor.

    #[ORM\Column(type: Types::ENUM)]
    private ?ProjectStatus $status = ProjectStatus::Open;

    #[ORM\Column(type: Types::ENUM, options: ['values' => ['open', 'locked', 'confirmed']])]
    private ?string $status = 'open';