You have waited a long time.
My AOS application (EB-1A) was also transferred to TSC in July, and there's not been any progress afterwards. My I-140 was approved last year, medicals were submitted along with AOS application, and biometrics was done in May 2021. This wait time is unsettling, but the lack of visibility is more frustrating to say the least. Can you share what worked in your case? Did you approach Congressman's office? Did you raise SR and/ or speak with L2 officer?