Hello, I am using the Shrine Pro theme, and I have added a quantity selector in the product information section.
Just want to confirm did you use licensed theme of Shrine OR Pirated one?
Because sometime pirated theme has a lot of issues with it.
Based on your confirmation I can provide you better solution.
Thanks
@JosueOtavalo - if you’re saying that the discount is not applied on checkout - it would mean that you’d need to setup the discount logic on the Shopify backend.
For any quantity / tier based logics you can check out “Dollarlabs: Ultimate Discounts” that allows you to set these logics up easily on the backend on a per customer level too if required 
Here’s a quick screengrab I lifted from the app’s listing page that better explains the capabilities.
This specific setup is used by Stores processing 100-200k$+ in a month, and we’ve built this to be fast & super stable.
Do feel free to reply / reach out if there are any doubts or questions, and I’d be happy to assist.
@JosueOtavalo Since quite some time has passed since you raised this thread, I’m assuming you’ve already reached at a solution
If so - can you please share the same and close this thread out so that others who stumble here might also find value.
Best,