MailChimp queue stops because of giftable by woocommerce

I’ve set up the cron job to run the command wp queue listen to sync the woocommerce orders with MailChimp. However, the queue has stopped due to this error:

PHP Fatal error:  Uncaught Error: Call to a member function get_type() on boolean in /var/www/vhosts/xyz.com/wp-content/plugins/giftable-for-woocommerce/includes/DGFW.php:536
Stack trace:
#0 /var/www/vhosts/xyz.com/wp-content/plugins/giftable-for-woocommerce/includes/DGFW.php(564): DGFW->is_gift(Object(WC_Product_Variation))
#1 /var/www/vhosts/xyz.com/wp-includes/class-wp-hook.php(288): DGFW->order_get_items(Array, Object(WC_Order))
#2 /var/www/vhosts/xyz.com/wp-includes/plugin.php(208): WP_Hook->apply_filters(Array, Array)
#3 /var/www/vhosts/xyz.com/wp-content/plugins/woocommerce/includes/abstracts/abstract-wc-order.php(730): apply_filters('woocommerce_ord...', Array, Object(WC_Order), Array)
#4 /var/www/vhosts/xyz.com/wp-content/plugins/mailchimp-for-woocommerce/includes/api/class-mailchimp-woocommerce-transform-orders-wc3.php(153): WC_Abstract_Order->get_items()
#5 /var/www/vhosts/xyz.com/wp-content/plugins/mailchimp-for-woocommerce/includes/api/class-mailchimp- in /var/www/vhosts/xyz.com/wp-content/plugins/giftable-for-woocommerce/includes/DGFW.php on line 536