Why was I asked to upgrade to Deluxe edition in order to get the Retirement Savings Contribution Credit?

While filing my taxes, I was asked to enter information for a Retirement Savings Contribution Credit. It said I was eligible for this credit, but would need to upgrade to Deluxe edition to receive the extra amount of refund (over $500). After upgrading, it stated that the amount was already included in my refund (which does not make sense to me). So, why did it state I had to upgrade if it did not maximize my refund as it stated it would? I would like to use Free edition if it is not going to add the additional refund for the Retirement credit.