Just yesterday there was a post on Pet People FB group, one in the dog shaming category but cute. The caption with the photo said, "I bark at doorbells on TV. We never had a doorbell!"
My response to that was, "Genetic wisdom."
I said that mostly to be funny but I also kind of sort of meant it in a way.
As it turns out, I might have been more right than I thought.
So perhaps the pup was never exposed to real doorbell, his parents might have. And perhaps that's the reason he's reacting to the sound of doorbells on TV. Or perhaps he just doesn't like the sound.
Always give your dog the benefit of the doubt.