If a Sternify bundle adds or refreshes incorrectly in UpCart, check UpCart’s Ajax compatibility option, then test the same bundle again.
1. Enable compatibility
Open UpCart → Cart Editor → Settings → Advanced Settings.
If your version offers Enhanced Ajax API compatibility, enable it and save.
Reload the storefront product page.
If your UpCart version shows this option, enable Enhanced Ajax API compatibility.
If this option is absent, ask UpCart or Sternify support for the current equivalent.
2. Test the cart
Use an empty cart. Select a Sternify offer and add it with the product page’s normal add-to-cart button.
Check the products, variants, gifts, and quantities in UpCart, then the final discount at checkout.
Repeat with any sticky add-to-cart or quick-buy button you use.
Checkout is correct; drawer is stale
A cart-refresh issue.
Items or quantities are wrong
The offer and exact add-to-cart button used.
Items are correct; discount is wrong
The checkout discount result.
Two drawers opening? Choose one cart drawer. If you use UpCart, check whether Sternify’s cart drawer is also enabled and turn off the unintended drawer.
Done: UpCart refreshes with the complete offer and checkout shows the expected total. If it still fails, send the product URL and a short selection-to-checkout recording.