I have this same issue except I had 4 ovarian torsions on both ends of a 13cm benign cystadeoma on my right ovary. They took the ovary left the tubes and other ovary and tube and where my ovary used to be is this intense dull ache (kind of like cramping) that I thought was associated with my period but it's all the time.
The only thing I could think of is remnants for your case and mine. Maybe a cyst was just forming again or not caught on the scan... make sure to keep advocating for yourself because docs tend to not believe women even female doctors! If you find out what the pain is drop a reply so we can know. I'll do the same. I'm about 3 months post op.