I had same situation
I had done 1st FP ,then biometrics, then code1 FP. I got code 1 FP notice right after biometrics. I went for the FP and asked officer. I was told it is bacause my 1st FP is expired. I had don't the code1 FP last August. Since then my file didn't get touched. My I-140 was filed in Jan.2003