Hi,
Your case (EB2-NIW) timeline is similar to mine. My I-140 was approved on July 9, 2020, and I applied for I-485 on November 8, 2019. I received the RFE for I-693 in November 2020 which I submitted by December 10, 2020 (updated on case tracker). I have been waiting ever since. Have you tried raising an SR?