Small update:
I have an M2 pro MacBook at work (different from my new M3 pro at home, which is having the issue). Just for fun I checked it this morning. The voices will download just fine and it is on Sonoma 14.1.1. So my original theory that it was the system update may not be entirely correct.
Either way, freesf’s reaponse made me glad I didn’t proceed with their tech options. I had totally factory reset the system due to an unrelated reason, which is why I lost the voice I’d downloaded in the first place.
Either way I’m hoping they can fix it somehow. I won’t be resetting again.
@freesf- what did they tell you the next steps were now?