Mbappé has actually caused problems for both teams. During his time at Paris Saint-Germain, the entire tactic was built around him. Now, Real Madrid is facing the same problem. They're building a tactic around Mbappé, but they're not acting as a team player. The manager should remember that Mbappé is a team player and guide him accordingly. Perhaps they can achieve more success through teamwork rather than individual efforts. Paris Saint-Germain is playing as if they've activated their god mode since Mbappé left the team.
The actual problem of Kylian Mbappé is greed, like he always plays for his individual performance, not for the team. In a team, all players need to contribute, while Real Madrid has a lot of top players, and everyone is hunting for his own individual performance and honestly, this is the reason behind the lack of the Real Madrid team although currently there are so many big names.
Similarly, they have the same problem happening which PSG has faced for many years. Like when PSG had many top players, the coach couldn't reunite them and the same is happening with Xabi Alonso. It is difficult for Xabi Alonso to use Mbappe, Vinícius, Bellingham, and Valverde together.