Shopify has a wide range of convenient apps, but you need to be careful when using them together. The attached image shows a case where a discount app interferes with the optional features when ordering, but it can cause unexpected behavior. We recommend that you thoroughly test the operation rather than just installing it and seeing that it works.
An example of using both a delivery date and time designation app and an app that allows specific members to purchase items at a discounted price
Reason why the delivery date and time was not set
