I've read and commented on your earlier posts about Beau. I assume the Vet check did not show any hearing problems or thyroid. Some do not want to swim or retrieve till after a year old and not all Labs want to, ever. Have you tried swimming with him? He was still young this past summer though, maybe need to try again next summer. Assuming you've had snow, Ontario has. Maybe Beau is just so confident he doesn't fret when you are gone? Maybe you have done such a good job at making your comings and leavings low key he just doesn't react? Mine didn't even come to the door when I got home and if they were there I followed the tip of ignoring for 10 minutes before acknowledging them. I don't want hysterics when I come home in case it means the dog is stressed when I'm out.
Mine seemed happy with other dogs too. But if our walk took us away from them my dogs came with me. Does Beau do that? We are lucky to be able to walk in large areas off leash, not dog parks.