Dark Spots not fading

Hi guys,

Has anyone felt that their dark spots or pigmentation dont fade away after reaching certain level?

Like I had acne and idk how but the spots I get pimples on get hyperpigmentation regardless of whether i pick on it or not. I had another break out last year and my face was filled with dark spots.

I made a routine suitable for my sensetive skin and followed religiously , most of the dark spots went away but some of them are not getting lighter. This happed to me last time too like my pigmentation would lighten to a certain degree but then it would remain the same no matter what i use or do.

Can someone suggest me what to do? or what products would help?