Agree, you are correcting the puppy why? If the pup doesn't understand what you want from him, there is no reason to correct him. You are the one instigating the 'battle' with your jabbing/claiming space and removing what he's focused on.
Redirect him instead when he starts mouthing and keep his confidence level high, work his little mind as it is in the sponge stage right now. Praise him when he's doing great!
When baby pups are tired, they get mouthy, that's a good time to place them in a crate with a safe chew.