Hi @lat9, thanks for your reply. Under this directory, I can only find "tpl_ajax_checkout_confirmation_default.php" but not "tpl_ajax_checkout_confirmation.php". Anyway this file is unchanged.

This duplicated order issue is still rare to happen on my end. I suspected that it might be related to the slow site/plug-in. But anyway I will report if it goes worse. I will add a note asking the customer to click the "submit order" button just once. Maybe it will help.


Thanks again.