It might be that he doesn't want to be alone. He is a cavalier after all (lol). Is he alone a lot throughout the day? Or maybe the opposite- he has a lot of company and then is alone to sleep at night?
Personally, I like my dogs sleeping our bedroom. They have their little beds on the floor and they snooze there all night until it's time to get up. When they were pups and crate training, I had them sleep in the kitchen alone, where we would get up once or twice in the middle of the night to let them out to potty, etc. When they were old enough to go through the night without a potty break, they came to our bedroom.
A dog is a very social animal, they don't like isolation. Although, it is important to teach them how to be alone, just for their own sake. I fostered a rescue dog who suffered from severe separation anxiety, it was heart-wrenching. We couldn't leave the house or else she would bark, cry, and scratch and chew at the walls and door. Nothing we did helped her, even with our girl Belle, who was the only dog there at the time. The situation was actually upsetting Belle, who began hiding behind doors and furniture to get away from the foster dog. The foster dog was lovely, had some initial small problems at the start, but the separation anxiety thing was a tough one. I ended up staying at home all the time, because I worried.
I'm sorry this is a long rant. But, I firmly believe that dogs need to learn how to be alone (for short periods of time). Yet, some dogs, who I see in my neighbourhood... live in such lonesomeness. It's awful, nearly worse than starvation. Dogs are social animals, some more than others, they just want to be with their pack. Can you let him sleep in your room? Might solve a lot of problems. Just have his bed there and he'll know that is where he goes.
Good Luck and let us know how you do.
Desrae, guardian of two tri-coloured cavaliers, Belle 3 years old and Bobby 1 year/8 months.