Variable virtual product

Hello,

All the products of my market place are variable AND virtual.
I can set it to virtual when it’s a simple product but not when it’s a variable one.
I tried this solution (found in an other topic) :

add_filter( 'wcfm_product_manage_fields_variations', function( $variation_fileds, $variations, $variation_shipping_option_array, $variation_tax_classes_options ) {
	$variation_fileds['is_virtual']['dfvalue'] = 'enable';
	$variation_fileds['is_downloadable']['dfvalue'] = 'enable';
	return $variation_fileds;
}, 50, 4 );

But it doesn’t change any thing.

Any ideas ?