She talks about it in-depth here.
I haven't listened to the whole thing, but it sounds like the thing that pushed her over the edge was them not including Candiace's live talking about the plot. She says her kids are questioning her being on the show, and doesn't ever want them to think she chose the show over them. She think Candiace and others skate by without accountability, while her feet are always held to the fire.
She said how dare Gizelle suggest that she'd be so desperate for a storyline that she would bring up a rumor involving her own child.
I understand the idea that the show is biased. BUT, to be fair, the producers had her back in part 2 and aired footage that supported things she said, even when Andy was being obtuse.