Waiting on I485 Approval post RFE response

Hey guys I had my biometric and interview done for my I485. I got RFE and I responded back to it back in Sept. Since then I can see status is "Response To USCIS' Request For Evidence Was Received". I don't see anything happening. I reached out through senator and I reached out on call. Everywhere I get response saying local USCIS office working on my case. Anyone else experiencing something similar? How long will it take for GC to get approved? Any idea?