Hair refuses to grow longer than 1mm to 5mm in length. Been like it for many months

I had a transplant of 5500 grafts march last year. About 20% of my hair is between 1mm and 5mm long and has been that length for between 8 and 6 months. It is rooted and will not come out when pulled. I have scrubbed hair. I have tried massaging head. Tried taking ginkgo biloba tablets. My surgeon has no idea. Most of the hair that refuses to grow is in the crown area and is mostly 1 or 2mm long. Any ideas what it may be or is it just dead.