GOOD CATCH! I hadn't even thought about that, but you may have just sussed out the issue. It will take a bit before his scent takes over the space and it is totally "HIS."
This is a great thread @weezercat and @Mamanyt1953.
I just had a thought about his being afraid of the tv and smell-tasting it. You say your previous cat only died just recently, well, his scent markings may still be noticeable to Calvin's super sensitive nose. Cats can become jealous about the tv, computers, and whatever else is drawing our attention away from them so they rub around them to claim them as their own. Was your old cat neutered? If he wasn't he might have sprayed on the tv for the same reason. Even if he was neutered, he may have still sprayed because some cats can continue to spray sometimes. Try cleaning your tv to see if wee Calvin becomes a bit braver. In fact, your whole house will smell of your old cat to Calvin's nose, and it will take him a while to get used to it and over-scent it with his own unique smell.