Hyperpigmentation after NDYag treatment of Cafe au Lait Macule?

I am 38 y.o male (Causian x Middle Eastern with mediterranean type skin, don't sunburn easily). I have a Cafe au Lait Macule on my chest since birth. Last year I was looking to have it removed. All the lit points to NDYags as the treatment of choice. I went to a local Plastic Surgeon and had 2 treatments (1 in July 2023 and 1 in December 2023). In between and after, I was using Hydroquinone 4% topical. It's been 4 months and still seems hyperpigmented at tx site. What should I do