Hi, I'm not sure if this already known. Some of the chapters have their B-Side listed at the wrong checkpoint. On the map screen, Chapter 1 has its B-Side listed at the first checkpoint, Crossing, but it can actually be found after the second, Chasm. Similarly in Chapter 6, it's listed at Lake, but is actually found at Hollows. I haven't checked every chapter to see if this is the case for all of them. I'm on the Switch version.