TBH, I don't think it's a matter of being "more likeable".
This person simply wasn't the right fit for this team, and there's no way around that. His exact behaviour would have been very well received at some of the places I worked and, but poorly received in others.
I don't think that putting an effort in "not being oneself" is really the key here. The key here is finding a team that's the right fit.