If I edit an order in WooCommerce, are the changes updated in the GT Backend?
Generally speaking, alterations made to an order in WooCommerce after it has been sent to GlobalTill are not reflected in the GT Backend. Remove the additional reference number from the original customer order in GT, delete the original customer order in GT, then re-pull the updated WooCommerce order back into GT.
WooCommerce can be customized to update existing GT orders, eliminating the need to re-pull, using appropriate webhooks. Reach out to your WooCommerce developer for more information.