Timeline:
August 2018 filed AOS with I-131, I-140, etc etc)
July 2019 interview for two year green card, approved next day.
13 April 2021 filed I-751.
27 August 2021 biometrics waived.
Case transferred to California Service Center.
Mid-January 2022 received RFE dated end of December 2021.
15 March 2022 mailed in our response to the RFE
18 March 2022 response to RFE received.
30 March 2022 approved! Card being produced.
Details: In January 2022 we received an RFE for my husband's I-751 that we filed last April. It was a form letter very similar to others I've read here, saying they needed more evidence for our marriage. At the top they listed the evidence they received from us. Over half of the items we sent were missing. We were pretty sure they simply lost it but it was still really stressful because of the language they used. For example, we provided our IRS tax transcripts (which they listed as received) but they said they were insufficient to show we filed taxes as a married couple (huh?) and they needed a version with all attachments (we did send W2s and 1099s in the original package but of course they lost those.... still not sure how they got separated from the transcripts?!). We put together another VERY FAT package including everything they had "lost" plus a bunch of other stuff and sent it off to the California Service Center, and today, less than two weeks later, he received a notification email that his 10 year green card is being produced! We are so relieved.
Anyway, I just wanted to post this in case anyone else has this issue and is searching the forum for answers, because frankly we were pretty panicked when we first got the RFE. I know this forum has helped us a great deal on our journey and I would like to give a little back. Thanks to everyone else who posted similar situations. It helped calm our nerves a little bit during the process of putting together our second package.