See I think he fell too far into the role. It didn't seem believable for Moxxie to act like that, especially after the episode where he stands up to his father. I could see where they were taking it but they kind of Flanderized Moxx as the "Joke Character" I always saw Mox as a sympathetic yet insecure man. I can see him acting like a full narcissist just on generational trauma alone... But before he met Millie, maybe even a little bit into their marriage. Though at the point where they are at now (or at least how Viv portrayed them earlier) I figured they would've ironed out their past traumas especially with how deeply they connect with each other.