Hi yenchin ,
Thank you very much for your post.
I’m terribly sorry, but I’m not sure what you are referring to. What pre-orders do you have in mind? ATUM itself does not handle any pre-order products.
If you have installed a plugin that manages pre-orders, it’s possible that it creates a different product type that ATUM cannot recognise. In that case, there would be an incompatibility issue.
Best regards,
Pavel