Error when using Gravity Forms Product plugin

I am using the Gravity Forms Product add-on (https://woocommerce.com/products/gravity-forms-add-ons/)

When I use their class to hide items from the cart and invoices it triggers a fatal error with PDF invoices: (The class is added to a gravity form field to hide that field: wc-gforms-hide-from-email)

An error of type E_ERROR was caused in line 55 of the file /home/MYSITE/public_html/wp-content/plugins/flexible-shipping-ups/classes/order-meta.php. Error message: Uncaught ArgumentCountError: Too few arguments to function Flexible_Shipping_UPS_Order_Meta::display_meta_key(), 1 passed in /home/MYSITE/public_html/wp-includes/class-wp-hook.php on line 286 and exactly 3 expected in /home/MYSITE/public_html/wp-content/plugins/flexible-shipping-ups/classes/order-meta.php:55 Stack trace: #0 /home/MYSITE/public_html/wp-includes/class-wp-hook.php(286): Flexible_Shipping_UPS_Order_Meta->display_meta_key(‘_gf_email_hidde…’) #1 /home/MYSITE/public_html/wp-includes/plugin.php(208): WP_Hook->apply_filters(‘_gf_email_hidde…’, Array) #2 /home/MYSITE/public_html/wp-content/plugins/woocommerce-gravityforms-product-addons/inc/gravityforms-product-addons-order.php(77): apply_filters(‘woocommerce_ord…’, ‘_gf_email_hidde…’) #3 /home/MYSITE/public_html/wp-includes/class-wp-hook.php(286): WC_GFPA_Order->custom_order_item_meta(64538, Object(WC_Order_Item_Product), Object(WC_Product_Simple)) #4 /home/MYSITE/public_html/wp-includes/class-wp-hook.php(310): WP_Hook->apply_fil