Cart showing wrong prices

Subject: Bug: Incorrect price calculation in cart on quantity update (AJAX)

We’ve encountered an issue with the price calculation in the cart when bulk discounts (e.g., discounts starting at 10 units) are involved.

Steps to reproduce:

1. Add 10 units of a product to the cart (the discount is applied correctly).
2. Go to the cart page.
3. Decrease the quantity from 10 to 9.

The Issue: After the cart updates via AJAX, the 9 units still show the discounted price instead of switching back to the regular price. However, as soon as you proceed to the checkout page, the total recalculates correctly and shows the proper non-discounted price.

It seems like the AJAX update on the cart page either caches the previous state or pulls the wrong price variable (potentially the one from the product page that displays what the price would be if they bought 10).

Is this a known bug, and is there a fix or a specific hook we can use to force a clean re-validation of the cart items on quantity change?

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