Sync GTIN for variations to SQUARE

We are using the offical WooCommerce Square plugin and we need GTIN to sync with Square. Simple products work but variations with GTIN fail. This is the following error in the debug log.

We are trying to sync product variations that have GTIN numbers from WooCommerce to Square. When we run a sync these are not coming over for variations and we get the following error in the debug:

2021-01-15T20:49:19+00:00 CRITICAL Uncaught Error: Call to a member function update_meta_data() on bool in /wp-content/plugins/product-gtin-ean-upc-isbn-for-woocommerce/includes/class.product-gtin-wc-admin.php:221
Stack trace:
#0 /wp-includes/class-wp-hook.php(287): WPM_Product_GTIN_WC_Admin->save_gtin_product_option_on_variation(1087, 2)
#1 /wp-includes/class-wp-hook.php(311): WP_Hook->apply_filters(”, Array)
#2 /wp-includes/plugin.php(484): WP_Hook->do_action(Array)
#3 wp-content/plugins/woocommerce/includes/admin/meta-boxes/class-wc-meta-box-product-data.php(541): do_action(‘woocommerce_sav…’, 1087, 2)
#4 /wp-content/plugins/woocommerce/includes/class-wc-ajax.php(2133): WC_Meta_Box_Product_Data::save_variations(482, Object(WP_Post))
#5 /wp-includes/class-wp-hook.php(287): WC_AJAX::save_var in /wp-content/plugins/product-gtin-ean-upc-isbn-for-woocommerce/includes/class.product-gtin-wc-admin.php on line 221