Currently the main problem for Real Madrid is the selfishness. Xabi Alonso is also aware of it and wants to take immediate action about it. The board is fully supporting him in this.
Mbappe, Bellingham, Vinicius Junior... These are the first selfish names standing out in the squad now. If their attacking line learn to play as a team instead of an individual only, I believe in Real Madrid to be a superb team just like PSG now...
This problem is not new to them. Although I can't speak in depth about Bellingham, the accusations against Kylian Mbappe and Vinicius Junior are not wrong. Mbappe's former PSG team has seen some conflict with Messi and Neymar over this. Vinicius Junior's selfishness is even more evident in the Brazilian national team. The only problem with Real Madrid's attack is selfishness. Even though they have the best attack line in the world, they keep a clean sheet in some matches, mainly because of this selfishness. I think Real Madrid should learn how to perform as a team from teams like Barcelona and PSG.
In reality such allegations about these players are truly reprehensible because it is true that they should only have the support of the new coach. It is now blindingly Obvious that Mbappe a former player for Paris Saint-Germain Football Club was not able to bond well with that team. You mentioned that Vinicius Junior is accused of selfishness in the Brazilian national team but in fact he does not have such a distorted talent hidden within him.