Paypal Payments don't show selected options

We're experiencing an issue with a site where invoices come in without options when paid via Paypal.

If the order is paid via credit card, the invoice correctly shows the selected options.

I've looked over code and have no idea why it's going wrong, none of it is customized as far as I'm aware.

Version 2.0.0.0

OpenCart 2.0.0.0 had various issues, you should upgrade.