Wishlist causes WPML Cart Sync to not work

Hey there,

So a strange issue is occurring on my site. I am using WPML and I sync my cart so when someone decides to switch form one language to the other, the items remain in the cart. However, when version 1.8.0 or higher of this plugin is active, it will delete the items in the cart when switching from the primary language to the secondary language or wont even add items to the cart in the secondary language.
My site is: https://zwei-design.com

Steps to reproduce the problem:
A. Select a product and add it to cart in the primary language (EN).
B. View the cart and switch the language to German (DE in the top right corner).
C. Then switch back to English
You will notice the product will delete itself from the cart.

Or simply start the whole process in the secondary language (German)
A. Go to the German shop page.
B. Add a product to your cart
C. Click “Warenkorb anzeigen”
The product will never be added to the cart.

The plugin appears to be storing the information of the visitor and its cart, so that he can access it later if he does not complete its payment.

I rolled back the plugin to version 1.7.4 and everything works perfectly again. I guess since version 1.8.0, there is some conflict with WPML or another plugin that I am using.

Any thoughts?

Many thoughts.

The page I need help with: [log in to see the link]