Unfortunately this is a problem that's been popping up since the game first launched (as you noted). I was hoping the definitive edition would have this issue fixed. I really hope they're planning on patching in the other player's voice functionality because it's frustrated me and my fiance to no end that he's not able to hear his character's voiced dialogue in these reflections. If anyone has a workaround I'd appreciate it too, because it drives us both crazy. I really hope Larian is still working on the problem!