Karl Zéro did not work for me

I watched Alain Delon, l'ombre au tableau (2019) and Karl Zéro was one of the parts I kept noticing. I do not hate it, but it did not pull me into the story. Some emotions are too simple, and I cannot believe the character enough. Many moments pass very fast, and I do not remember much after them. For me, it does not feel very real in many scenes. I remember both the good parts and the parts that did not work so well.