Indents in injection site after fat grafting. Should I be concerned and will this go away on its own? (photo)

This traumatic indent in your forehead can best be "fix" by riggotomy and adding HA fillers or better yet nano/micro fat grafts. Fee $1,000. Best to virtual consult with...

You didn’t include the timeframe of how long ago your procedure was.
Based on your picture it looks like it’s been more than a few months and you can expect the dead incision site is not going to change with further waiting.
Was this done by a board-certified plastic surgeon?
Placing an incision in the center of the forehead is a very odd place to do grafting. Most plastic surgeons would make a decision sites and visually far less obvious places like the edge of the hairline or the edge of your eyebrow. It’s an unfortunate place to put a scar being right smack in the middle of your forehead.
It may look like a very small problem but you may find that it requires a full excision with sutures to correct properly.
I would trust the plastic surgeon more than the dermatologist to correct this. Look for plastic surgeons who are meticulous and detail oriented.
Plastic surgeons that specialize in facelift and rhinoplasty for example.
An attempt at correcting your forehead and scar can very quickly make it worse if not done by someone who has sufficient skill and experience. The placement of your incision site is definitely one strike against your current provider and if you were looking for further work consider consulting with other providers first. It shows a lack of insight and common sense.
Best,
Mats Hagstrom MD