Help Player development has plateaued

[Heskeynho]

Guys, I’m on my second season on a hamburger sv save. I have a huge issue, I have 9 players plateaued... this is extremely annoying, am I meant to loan them out? Or bench them? Or put them in reserves for a bit or what. Most of my team is wonderkids and this is becoming wonderfully frustrating....
Has anyone figured out how to fix this?
 

list of plateaued kiddos:

Ivan Martinez, vagnoman, Toni herrero, Bellanova, Adrien fein, ansu fati, robér, amaechi, and arezo.

 

[samhardy]

Bit of extra information in here but I don't think there's a definitive answer.

 

[Nicksaban]

Yeah the game is broken my below 24 years players are declining and can't improve mentally