Could not retrieve a taxonomy block type data

Hello !

Can you help me with that ?

Block:

function waff_blocks_register_meta_boxes( $meta_boxes ) {
	$prefix = 'waff_';

	// WA Partners
	$meta_boxes[] = [
		'title'           => esc_html__( '(WA) Partners', 'waff' ),
		'id'              => 'wa-partners',
		'fields'          => [
			[
				'id'         => $prefix . 'pn_categories',
				'type'       => 'taxonomy',
				'name'       => esc_html__( 'Select categories', 'waff' ),
				'taxonomy'   => array('partenaire-category'),
				'desc'       => esc_html__( 'Choose to display those categories. If empty, none of the categories will be displayed.', 'waff' ),
				'field_type' => 'checkbox_list',
				'multiple' => true,
				'select_all_none' => true,
				'query_args'  => array(
					'post_status'    => 'publish',
					'posts_per_page' => -1,
				),
				//'hidden' => array( $prefix . 'lp_posttype', '!=', 'post' ),
			],	
		
		],
		'category'        => 'layout',
		'icon'            => 'megaphone',
		'description'     => esc_html__( 'Display the current edition partners', 'waff' ),
		'keywords'        => ['partners', 'posts', 'partner', 'logotype'],
		'supports'        => [
			'anchor'          => true,
			'customClassName' => true,
			'align'           => ['wide'], // left, center, right, 
		],
		'render_callback' => 'WaffTwo\Blocks\wa_partners_callback',
		'type'            => 'block',
		'context'         => 'side',
	];

        ...

Render:

function wa_partners_callback( $attributes, $is_preview = false, $post_id = null ) {

...
print_r(mb_get_block_field( 'waff_pn_categories' )); // Could not retrieve taxonomy datas
...

Front:
Array( ) is always empty..

Thanks a lot,
Wilhem