I feel Giaime Grieco is not convincing

For me, Giaime Grieco's work in I'm Back (2018) is easy to talk about after watching. Many moments pass very fast, and I do not remember much after them. Some emotions are too simple, and I cannot believe the character enough. The role needs more detail, but the performance stays on the surface. I do not hate it, but it did not pull me into the story. Maybe other people will like it more, but this is my feeling.