Not sure what "blue" mountain is (Trial Mountain? Mount Panorama?), but I'm guessing that you set your "gold" time quite some time ago?
GT7 has had two major physics changes, and after each the times required for licences (and other events) are adjusted to account for the change in difficulty.
When you set a time you get the rewards appropriate to the boundaries at that time. If the boundaries increase and your time now falls into a new bracket, you don't then get the rewards for it - because it wasn't good enough to do so when you did it. You have to set a new time to get them.
Your old time will still show but you'll notice it's not on the leaderboards because it's not valid for the current physics.