Solved

Manager 14 avec pilote 18??

There is a, now rather rare, case how that can happen. Drivers in the old version of iGP had more and different attributes and thus a different way to calculate the level. If such a driver never had a skill up in the new version then he's still showing his level from the old version, after a manager buys that driver and trains him the next skill up will trigger a recalculation of that drivers level according to the new weighting of the remaining attributes which raises the level by 3 or 4. Such a driver can be identified that his history shows that before the current team the last fired him in 2014 or so.

The other way would be spending a huge amount of token to train him there despite the progress per unit is reduced to 3%.