What was wrong with their portrayal? They’re the same people we know them from ROTJ with the exception of sharing a loss that has led them to splitting up.
Leia didn’t really have a role in the movie. She was just “there”. She doesn’t even acknowledge Chewie after Han dies. Instead she’s consoling someone she barely knows because welp, the filmmakers needed to foist some kind of female character connection upon the audience that they weren’t skilled enough to establish in a dramatic way throughout the rest of the movie.
Han was better because he had a legitimate role in the movie, but the role was still more in line with Kingdom of the Crystal Skull bullshit than Star Wars. At no point in the movie did I ever feel like Han Solo was a serious character. He feels like he’s an action figure in a comic book universe.
And I can’t even get started on this whole thing with their supposed son. There is nothing emotional or dramatic about any of it because these people never share a history together on screen. Characters don’t earn those emotions through a few lines of expository dialogue. He’s Han and Leia’s son…because the writers told us. Oh look, he killed Han. How sad! Just no, no, no. That’s not how it works.