I had the same issue a few months ago when I was trying to ask LLMs about Box2D 3.0. I kept getting answers that were either for Box2D 2.x, or some horrific mashup of 2.x and 3.0.
Now Box2D 3.1 has been released and there's zero chance any of the LLMs are going to emit any useful answers that integrate the newly introduced features and changes.