I may be wrong but this young man has a speech impediment that might indicate he has a hearing problem. This might explain his studied manner.
I think English might be his second,third,or fourth language. He is very often on YouTube and I’ve watched him many times. I think it is probable that he was uncomfortable with both national television and Carlson. With people that are comfortable with him,i.e., know he responds to questions and defers to you until you ask one, he is a joy to watch. The man is brilliant and very engaging. Trump should spend 15 minutes every day with this man and should hire him as his speechwriter.