Thank you for reaching out to the Community! I'm happy to provide some assistance with Buy X, Get Y discounts to ensure this gets resolved. To confirm, are both the Buy X and Get Y products being added to the cart?
If not, this would be expected behaviour for this type of discount. While I can completely understand how this may not be ideal, all items must be added to the cart for the discount to apply. The "Get Y" items will not be automatically added to the cart. For more information on discounts, you can check out our Discount Types documentation as it touches on this further.
In the case both items are being added to the cart and the discount code does not apply, please feel free to Contact Support for further investigation. This will allow our advisor team to take a closer look and ensure it gets resolved as quickly as possible.
Please let me know if you have any other questions or concerns.
Blair | Shopify - Was my reply helpful? Click Like to let me know! - Was your question answered? Mark it as an Accepted Solution - To learn more visit the Shopify Help Center or the Shopify Blog