By default, our "smart" cart feature is turned ON, which will show Handpicked Cross Sells in your cart page based on the products added to it. Here's how to turn off/on this feature to activate Global Cart Cross Sells:
Version1 of our app (check version in the Account section of the app):
Get in touch with us, or deactivate it yourself, by setting the "cssmartcart" variable to 'off' in our cross-sell.liquid file inside your Snippets folder (you might also be using a file named cross-sell-custom.liquid inside the Snippets folder, in which case modify the latter).
Version2 of our app (check version in the Account section of the app):
This is now a checkbox inside our app's Settings -> Cart/Basket Page Settings