The latest update brought a change to the way saves work in clubs. Prior to that, the save would only update after each stage, which meant that repairs done at a service wouldn't be saved if you quit...
Ideas
Followed all the steps and the same occurred. I'll also add that if you get a second service penalty, it's added to the total penalties incurred from the previous service. EG:
Second Service: 20sec Penalty
Third Service before SS7: 30sec Penalty
Time Penalty after SS7: 50sec
I was able to reset the penalties by entering a service area after a stage, closing the game, re-entering the club, fixing the car (keeping it below the penalty limit), exiting and re-entering the club again. Doing this showed no penalty on the next stage that followed after a service