Cart Validation API not running properly?

[marcreese]

Hello,

I’ve developed an app that relies on the quantity of line items remaining unchanged (only deletions are allowed).

To ensure this, I implemented a cart validation script in JavaScript and deployed it within the app to prevent users from modifying the quantity of specific products.

In my tests across different shops, the script works correctly in all scenarios.

However, some clients have reported that a few of their customers are still able to change the quantity despite the validation.

I checked the app logs in the Shopify Partner Dashboard and found no errors, everything appears to be running as expected.

Is there any known way to bypass the cart validation mechanism outside of POS?

I would really appreciate any help, as a few of my clients are quite upset about this issue.

Thank you very much!