I started playing again after a few months away when the South Africa storyline released. And every time one of the new cutscenes plays, there are no voices. The subtitles also don’t work. So I’ve literally got no idea why I ran off to South Africa. I got a phone call, and I didn’t get spoken dialogue for that, either. I did, however, get subtitles for during the phone call.
Note that background voices not in cutscenes work just fine. And sound effects play properly during cutscenes. It’s just the items mentioned above that don’t work.