Hello,
It is not normal to get vaginal spotting 6 months after your surgery. It can be due to pelvic Inflammatory Disease (PID), cervicitis, menopause, or sexually transmitted diseases like gonorrhea and Chlamydia .You should consult a gynecologist who will physically examine the local area and may consider tests for confirming the diagnosis.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.
This does not sound like it is related to the cyst. I would talk to your gynecologist about this any way and explain the spotting.