Hair under the hairline, won't grow back, why? (Photos)

This needs an in-person evaluation. I suggest seeing a hair loss expert now to evaluate and go over your condition and provide you information about your best treatment options. There are great non-invasive options like prp/progesterone and/or hair transplantation. See an expert. Best, Dr. Emer

These changes come about from a combination of genetic hair loss and hairline maturation. These hairs likely won't be present in a few years. Waiting is the best option rather than removing. 

Frontal hairs that don't grow often reflect genetic hair loss.  I generally perform a HAIRCHECK instrument test to see of there is hair loss that is not apparent from the naked eye. See post below