Dirty socks needs a damp spot to accumulate biological grow between cooling cycles. I have fixed it by operating the fan continuously between the cooling cycles. This dries out the entire duct/coil area between cooling cycles.
Suggest investigating your air handler and find the damp spot and clean it or shine an UV lite on it. Next dry out you ducts/a/c throughly a couple hours everyday. Drying interupts the biological growth cycle. In addition, I discharge my whole house dehu into the supply ducts which keeps everything dried out. I maintain <50%RH throughout the home. I also provide 60-80 cfm of fresh air via the dehu when the home is occupied. No DDS after that treatment. Regards TB

