Need Advice Regarding Protein Powder

Its been 4 months since ive started gyming and 1.5 months since i am using Atomic Muscle protein powder. I am getting gains but im not sure if its because of the protein powder.

My Case:
M29 Weight 85kg 5'10 height.
Goal: Lean Muscle.
After 4 monts of Gyming
Weight 83kg, muscles increased, belly and body fat decreased, body started tonning.