Unwrap half of the model and then apply symmetry modifier to it. I recommend watching this tutorial if you havent already https://www.youtube.com/watch?v=Z9wgKy-F1Rw
Yep now you said it, it has to be definitively whiter. I will modify the roughness too. That should probably fix the problem. Thank you for your help !
Lathe is a modifier in 3ds Max that allows you to spin a shape and wrap it around with control. Useful for creating cylindrical shapes from line tool, etc.
Just wanted to update this in case anyone else has this problem. If you mirror things properly (using the symmetry modifier) you won't have this problem.