Why is my circle cast not going the full distance?

I did a circle cast sort of like this: Physics2D.CircleCast(origin, radius, vector, vector.magnitude, mask)

And an OverlapCircle like this: OverlapCircleAll(origin + vector, radius, mask)

For some reason the overlap sometimes detects something that the circle cast doesn't. This should never happen because the overlap is the last stage of the circle cast. Anything the overlap detects should also be picked up at the latter part of the circle cast.

I don't understand how or why this happens. I need to use circle cast because it returns more info about the hit, but I can't because it isn't reliable.