Are you resetting sport mode every drive? If you leave it set, next time you start the car it will say it's in sport mode but the throttle won't actually be in sport. It forgets and VW don't seem to have a fix.
In our GTD we have to switch to normal and back to sport to get the steering and throttle really into sport mode. Oddly it always remembers the exhaust, that always remains in noisy mode.