Yes, when I shade it smoot, it looks very smooth buuut, I get an odd shadow
You are using a mirror modifier, aren’t you?
make sure you don’t have faces inside the model where the 2 halves join.
If that’s not it, then go into edit mode, select everything, use “merge by distance” to make sure there are no overlapping faces then finally recalculate normals direction with shift+n.
Unsure if anyone mentioned it and I am sorry but I did not saw it… however did you consider using weighted normals? it might help I assume.
You’re right. Weighted Normals and your hint was the solution.
Many thanks for you patience