Jack
I upgraded 1 level - 15 to 16 and it has made no difference whatsoever.
Let's try a different way.
A driver whose level is higher than the manager's level gets hit with a training progress cap. If I recall correctly, a driver whose level is one level higher than the manager's, the cap is 3 points per click of the training button, 2 points for a driver whose level is two higher than the manager's, and 1 point for a driver whose level is 3 or more than the manager's.
Your driver is level 17, one level higher than your manager level. This is why you were unable to see any increases in progress.