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So I just got to Chapter 5: The Cave and now when I got control and have to walk up the stairs etc, I can't change character, I can only change to Kevin. And Big Joe is walking so slowly that it's hugely annoying having to just sit and wait to get anywhere. I've used a candy so Joe is at full Health and I've tried saving, loading, restarting the game etc, but nothing works. I looked at some let's plays and in all of them they could change character.

Any way I would be able to fix this?