When faced with criticism from an organization that doesn't know how to internalize criticism directed against itself, put on the most earnest expression you can muster and ask firmly but politely for concrete examples of "toxic behavior" that you've supposedly committed. Performance reviews, especially at large organizations, are not set up to help you improve. They're either a political device or a component of stack ranking that can be used as part of "documenting" a dismissal. Especially suspect are broad accusations that can mean practically anything but sound serious on the surface.

Definitely get more information before you go accepting blame for something that might well be a smoke screen.