Your donor area was either over-harvested if you had an FUE or developed a scar from a strip surgery which, when it occurs, usually occurs in that location. You did not state if you had FUE grafts and if so, how many or if you had strip surgery. If it was FUE, the number of grafts for that area was too high. If it was a strip surgery, most likely the wound was closed too tight which will cause this type of hair loss.
We obviously see complications from both (a) too many FUE grafts for a given area of the scalp and (b) strip wounds that are too tightly closed. Most doctors and patients think that the donor area can stand almost any stress but in this post I suggested that stress (FUE or strip surgery) can cause hair loss by impacting the donor area blood supply. You should wait this out and in about six months after the procedure, the hair may return. Scalp MicroPigmentation is a good option for this problem if it needs to be treated.
See link below.