WordPress Block Variation - not working for core/group

PHP:
		$variations[] = array(
			'name'       => 'damien-update-info',
			'title'      => 'Update Info',
			'icon'       => 'book-alt',
			'attributes' => array( 'className' => 'is-style-group-info' ),
			'innerBlocks' => array(
				array( 'core/paragraph', array( 'content' => '<strong>' . $date->format('j F Y') . '</strong>: information about the update ...', ) ),
			),
		);

JS:
wp.blocks.registerBlockVariation(
	'core/group',
	{
		name: 'dcwd-group-update',
		title: 'Update info',
		attributes: {
			className: 'is-style-group-info',
		},
		innerBlocks: [
			[
				'core/paragraph',
				{
					content: '<strong>' + new Date().toLocaleDateString('en-us', { year:"numeric", month:"long", day:"numeric"}) + '</strong>: Info about update...',
				}
			],
		],
	}
);