Inconsistent UX for Discount code validation

When I apply the Discount code and click Validate, the code appears to be successfully applied and the “Hurray!” message/animation is shown. However, after I enter the address and proceed, it shows an error saying the code cannot be applied.

This feels quite confusing and creates a discrepancy in the user experience. At one step, we are telling the user, “Hurray, the code has been applied,” and then in the next step, we are saying, “Oh no, you can’t apply this code.”

Wouldn’t it be better to validate the code when the user clicks Validate and show the error at that point itself if the code cannot actually be applied? This would make the flow clearer and avoid confusing the user.