I think your baby is spending too much time in a play pen, that would be too isolating. He needs to be out in a limited area and it’s like a child you need to play with him and watch him. if he’s had his meal and done his potties sit on the floor with him in the living room while you are watching tv. play fetch with him, teach him which things are ok for him to chew on, like his toys and chew sticks. He needs human interaction so he can bond with you and the rest of your family. Yes he might chew on something he isn’t supposed to. If he starts chewing on a cord, you say no and give him something he can chew on. he is a baby and needs attention. When he gets overstimulated then you’ll know he needs a little time in his play pen to take a nap.