SSR doesn't know how thick objects are. So a reflection ray that goes behind link's model assume his shape is infintely thick and extends all the way to the back walls, so it kills the ray there and retreats to tbe cubemap fall-back.
If the reflection on the cubemap fallback is lit enough at a certain spot, it might drown out all the direct lighting on top of it making it seem like the direct lighting is broken on that spot too, when in reality its in there just fine, but the cubemap contents are so bright it takes over.
Those are all guesses though.