Hello,
We process some test directly on your website, in details we try to add the Module 2 Product in the cart, and with success.
In order to allow us to better understand can you provide these elements :
- A step by step to reproduce your issue (be as detailed as possible)
- Relative settings screenshot
=> Be very specific in your explanation because we have the feeling that we are missing something in your problem, or why this does not correspond to your expectations or your settings.
Please help us clear up any confusion or misunderstanding.
Regards