Often someone posts about how their relationship is perfect except for this one thing about their partner, and they want to know how to get their partner to change.

What they often find, I think, is that it is a mistake to try to change someone, and that their partner isn’t interested in changing.

Maybe G will turn out to be different, although the blowout fight he had with J makes me skeptical of that. But if G turns out to be like many other partners, then the relationship you have is the one that you are going to have, and the question will be whether that is acceptable to you, or whether it is a dealbreaker.