We have a Cart Transform function that uses LinesMerge to collapse multiple component cart lines into a single customized bundle line. We set LinesMergeOperation.image, title, and cart attributes on the merge op.
We would expect the merged bundle line returned by Shopify’s AJAX Cart API (/cart.js, /cart.json) reflects all three overrides on the same line: title, price, and image / featured_image.
Checkout renders the custom bundle image correctly, so the function-side override is definitively being applied; the AJAX Cart API response is not reflecting the image instead it pulls the image from the first line item.
The problem here is that the cart is showing the wrong image and it is inconsistent with checkout.