I come back to the subject...
I bought a new computer, with a RTX 3070 Ti graphics card and I tried to replicate the same game in Godot and surprise...
It keeps doing the stutters every "x" seconds.... The stuttering happens just when it drops from 60 to 59 FPS, at that moment.
I still don't understand why this happens. I think it's the movement of the Camara2D but I have no idea how to fix this.
If I leave static, even if the game drops to 59 no stuttering is noticed.... But if the Camara2D is constantly moving, chasing the player, there if you notice a stuttering when it goes down to 59 FPS, especially in the environment (the map tiles).