I would think it's because the previous 3 eyed raven had time to acclimate while even thing the Bran is new. He probably needs time to adjust. Also it's probably a coping mechanism for all of the trama he had to endure and also see his family endure
Yea man. All them kids fukked up. Bran is emotionally unavailable, Arya went batshyt crazy and Sansa is jaded and cynical. Jon changed the least but he was the second oldest and his path wasn’t as fukked up as the others. Losing your mom, dad, both brothers, all your family friends, etc would have you in serious counseling irl.