Oh wow that's crazy!
I had a similar timeline in terms of application time. Applied for I751 in 9/21, didn't get any updates besides to say that Fingerprints were used a couple months after that. Didn't hear anything or see any changes until March 2023, got the notification that the case had been approved and I received my green card a week after that in the mail.
Hoping you won't be waiting too much longer!