He's 23 years old, at the start of the season. Do you think his overall should be locked at that age?
In my opinion it's just unrealistic and plain out stupid that players can't develop. It takes all the fun out of BaGM and makes no sense overall...
They should look at Fifa or Madden where a player can develop despite of their age, by performing well.
It makes me so frustrated when player performance does not have any effect in their development. I once started a season where Gudbranson had Elite potential and he developed up to 87 with only 1 goal and 5 assists that season. This time around he started with lower potential and had vastly better stats only to see him not develop at all.