Automatically inserted post needs update?

I have a function which automatically inserts a woocommerce product once a custom type post called daily_cartoon has been added.

This is the code of the function:

function convert_daily_cartoon_into_product($post_id){

	if( ( $_POST['post_status'] == 'publish' ) && ( $_POST['original_post_status'] != 'publish' ) ) {

		// Create post object
		$post = array(
		  'post_title' => $_POST['post_title'],
		  'post_type' => 'product',
		  'post_status' => 'publish',
		  'tax_input' => array( 'product_cat' => 14 )
		);

		// Insert the post into the database
		$new_print = wp_insert_post( $post );

		update_post_meta( $new_print, '_thumbnail_id', get_post_thumbnail_id( $post_id ) );
		update_post_meta( $new_print, '_regular_price', 5 );
		update_post_meta( $new_print, '_price', 5 );
	}

}

add_action('publish_daily_cartoon', 'convert_daily_cartoon_into_product');

Everything looks fine: the product is added, complete with all the data, i.e. price, category, status published, etc.

But for some reason, it doesn’t show up on the website product page until I go edit the new product and click ‘update’ – even though I change nothing.

Anyone?