Try to add the following PHP code snippet to the child theme functions.php file to fix this

add_action( 'after_setup_theme', 'woodmart_add_image_size' );

	function woodmart_add_image_size() {

		if( ! function_exists( 'wc_get_image_size' ) ) return;

		$shop_catalog = wc_get_image_size( 'woocommerce_thumbnail' );

		$width = (int) ( $shop_catalog['width'] * 2 );
		$height = (int) ( $shop_catalog['height'] * 2 );

		add_image_size( 'woodmart_shop_catalog_x2', $width, $height, $shop_catalog['crop'] );
	}