Driver losing a level after a race. Possible bug.

I trained my driver G Arenas before my race tonight at Valencia. He qualified 8th and finished 9th. But tbh in the league I'm in up agaisnt more experienced players that's not as bad as some of his results. But the weird thing I saw was, he was level 4 just after training, but then when I go and have a look at my drivers, he's dropped back down to level 3 again. ???

Go to training again and after I do that he's back to level 4. I would consider that weird and will have an eye on my drivers after the next race in my league which is tomorrow at Spa.

No bug.
From the rules:

So 34 is old? Fernando Alonso is 30 years old and I don't think he's getting any slower.

I would've thought that, maybe in a few years he would be in his last season and start to struggle, not so soon.

But he is. "I give up, I give up..." :)

Offcourse Alonso his skill can atrophy, this is why he is training all the time.
Furthermore, Alonso is a level 999 driver who can loose about 100 levels before we notice.

(BTW, I am not a fan of Alonso. I just objectively consider him in the top 3 drivers out there at the moment.)

So what at the moment is considered the cut off for a driver that where, getting better for them becomes difficult?

They all lose stats, [including under 20's] whether they lose more or less than older people i do not know, if you train every race then i've never seen a driver not improve, its only noticable when changing levels, say he has 97points [almost about to level up] he gains 3 from training[reaches enough to level up], then loses 1 from "atrophy"  he will drop down to his previous level, but next time he is trained, then races he will level up and stay at that level

older drivers atrophy faster. also when you are training past a level, like from level 3 to 4 then it can occur that the drivers level will go down after the race of course. also it depends on what attributes are trained.

then again Schumacher is still at it...