Someone else brought this up in the suggestion thread..
https://forums.ootpdevelopments.com/...d.php?t=366696 so it does happen.
I did respond there that it has never happened to me in 20+ years of playing OOTP. My classes are right where they should be age wise. I'd also guess it's not widespread or there would be a lot more posts.
The obvious question is why do some see it and others don't?
Have you ever sent in a save file for them to look at to perhaps find a cause?
Is your game imported and continued? Do you start a new game with each version and have the issue?
FWIW my game is imported from version to version. After the rewrite of 2006 I started using feeder leagues with both HS and College divisions. With feeders, once you had balanced classes, you could set the player creation ages for both HS snd college, IIRC. I used these feeder draft pools for a few versions.
Then OOTP went to a game created draft class that has stats, schools, etc. and I found them to be better than my feeder classes without the hassle of running feeder leagues. From day one these classes were created with players having the appropriate ages.
Again, I'm not saying the issue doesn't exist for you and others. But it is important for the developer to know that it isn't happening to everyone.
I do hope they find a solution for you.