I’m able to add items to our cart via the add to cart remote widget, and get successful update of our remote cart widget. I can also navigate to our shop domain and see the item I just added in my cart there, but when I click on View Cart from either the remote site or the shop domain site, the cart loads empty. If I click Checkout, an empty cart loads. Refreshing the other places (remote widget, shop domain) additionally shows an empty cart now.
Do you have an example URL for where the remote widgets have been added?
My guess would be that you’re using the older version of our “Add to Cart” widget which either needs a small code update or to get swapped out with our newer widget in order to work with the V2 checkout.