Eucerin .. what am I doing wrong.

This is how I am using it. Anti pigment dual serum after bath. Regular moisturizer a few mins later. Eucerin anti pigment day cream a couple of hours later.

Anitpigment serum again at night after cleaning face. Light moisturizer a few mins later. Eucerin anti pigment night cream about 30 mins after.

I have hardly seen any difference so far and it’s already been a month.

Any advice?