Just to clarify, the Cart API I'm referring to is this one: https://shopify.dev/docs/api/ajax/reference/cart#post-locale-cart-update-js.

Hi! I'm having a problem with the cart API. We are using the cart attributes and utilizing the Cart API for this purpose. The API we are using is 'cart/update.js'.  We are able to add new attributes and change their values without any issues. However...