Dear Thomas
I am on EB2 too. DQ: April 18 2023, PD: August 21, 2021 (current). I have contacted US embassy Frankfurt. They said case is with NVC so that they don't know anything about appointment.
Could you please tell me how long it took to get your interview letter (DQ to Interview)?
What did you write for your expedite request to NVC? (Reason)
Best Regards
Ahsan