Why is my custom discount code not working on the checkout page?

[Dev_Arc_Wayne]

We are experiencing an issue with our checkout page discount.

Details:
For the code, we have this: https://prnt.sc/XkpI69QC19qZ. We created this "BUNDLE DISCOUNT" code based on the cart items. For example, if a customer buys 3 pairs, they will get a 5% discount; if they buy 6 pairs, they will get a 10% discount; and if they buy 10 pairs, they will get a 15% discount, and so on.

Issue:
It was working properly before, but today, upon checking, it is not functioning correctly.

Observations:
During checkout, the discount is applied https://prnt.sc/oXCVAjzzQXms, but after a few seconds, it gets overridden, and the discount is removed https://prnt.sc/mynK1uvWPDdJ.

Uncertainty:
I am also unsure if the `checkout_type=c1` parameter is causing the issue https://prnt.sc/DuHefZ6Nve3X.

Store Link:
https://wamaunderwear.com/products/hemp-boxer-briefs

Thank you!