Position in Manager Career Mode

I don’t know if this is normal, but some players can’t train a position. For example, I can’t train Kimmich as a CDM even if he is stronger than on the RB position. I had this with different players mostly with the position CDM and CB. 

I don’t know if other people have this issue or if it’s just part of the game but then I would appreciate if someone can explain me when it is possible and when not to train the position with the players