Hello,
I am working on a project, and I noticed a strange issue with BoxRelectionCapture and SphereReflexionCapture.
You can see on attached file, the ReflectionCapture have not “fallof” or “gradient”.
I don’t know why…
Do you have any idea about this ?
anyme have this problem ? 
You actually have to make sure your whole Room is covered in Reflection Captures. PBR relies on Reflections.
But to answer your questions, somehow only Box Reflection Captures have a Transition Gradient (Box Transition Slider)
It’s because there should be at least 1 probe covering every section of the scene, with smaller ones where you need more accurate reflections.