Soak them overnight even if the recipe says you don't need to.
I made refried beans in the crockpot last week. They were great and I got to control the salt. I'm one of those weirdos who doesn't like salty food.
I always soak my beans beforehand, always. IDK maybe the altitude screws with my required cooking time. Anyway I got the cooking perfect bean with the pressure cooker down pat.