We don't know and we'll never know unless someone majorly screws up and violates client confidentiality... absolutely every response you'll get here will be speculation.
A pretty common cause for this sort of thing is that the lawyers feel unable to appropriately advocate for her - possibly due to a private admission. It could be something as simple as her revealing that she lied in a deposition (though if they knowingly hide this from the judge or opposing counsel they'll be in deep shit) or it could be sociopathic digressions when consulting firm members that are causing HR issues for the company. Lastly, she could be combative in private discourse and threatening to firm members. It's likely due to some kind of internal strife and, as her representatives, they can't reveal more without prejudicing the public against her - and that would likely get them disbarred.