A couple thongs come to mind:
- Did the microphone in the headliner somehow come unplugged? I had this happen in my previous '21 Audi RS5. No idea how the mic became unplugged, but same scenario; the car suddenly stoped responding to voice commands. Audi dealership diagnosed and repaired under warranty.
- Software update went wrong... this is the more likely culprit. But you'd need the dealership to test and confirm correct loading of all current software.