It still baffles me how Enrique just want to get rid of Donnaruma after all the things he's done for Paris Saint Germain, leading them to their first ever champions League and even winning a treble for the team and all of a sudden he's out of Enrique plan, something is really not right in that Paris Saint Germain team, Donnaruma is not a bad goal keeper to start with and I don't really think he has a record of bad behavior, but they just wanted him out to the extent of lowering his release fee, this is the same fate David De Gea face in Manchester United, I wish Manchester United will just get him at least he's far more better than Onana.
Sometimes a team may seem to outgrow a player and at that point it does not matter how much the player has gotten the team, they will just want to get rid of the player and maybe bring in a replacement they feel better suits and that may likely be the case here at PSG because Donnaruma is still in his good form and is doing so well with almost no challenge only that Enrique seem not to need him anymore.
In the last tournament PSG played, which is the Club World Cup, Donnarumma's performance for PSG was impressive, and if Chelsea hadn't surprised everyone in the Club World Cup final, Donnarumma would have helped PSG win the Club World Cup. Donnarumma is still one of the best goalkeepers in the world right now, and for Luis Enrique not wanting to work with Donnarumma this season at PSG, it is a clear indication there's a disagreement between PSG and Donnarumma this season.
You are right with your point once a couch starts disliking a good player not wanting to work with the player again and looking for a way to sell him out to other team know that all is not well there might have been a misunderstanding between the manager and the player.