I like to think that Kallus' behavior post redemption does a full 360°. Hear me out- as he becomes more comfortable being allowed to show "weakness" in form of empathy and general emotions he starts to have a softer approach to social interactions, especially with the Ghost Crew. But as he gains their trust more and they all grow more comfortable with him being around + he becomes more comfortable being around and not constantly feeling like an imposter, he starts to behave in a way that some might mistake for an emotional set-back. He's less gentle with his responses, making snide remarks here and there in addition to getting into a verbal spat with someone from the Ghost Crew every five minutes.
The thing is, at his core, Kallus is soft, gentle and caring - he is however also a bitch who will gloat when he wins an argument, be super petty during family game nights and laugh with genuine amusement when his loved ones do something - frankly - really fucking stupid.