Reflections - light reflecting through walls

Hello,

I’ve spent a while learning about lighting, volumetric fog and bunch of other things and decided to use most of that just for the sake of practice and made a scene shown in screenshot at the end of this post.

I have movable directional light shining through the right part of the scene and I tried making floor and wall on the left reflect the rest of it. I put a planar reflection on each and applied polished marble material from starter content.

Now here’s the problem: I can’t get rid of a specific reflection that shouldn’t even be there. Corners around ceiling at the end of this corridor are pretty much black, as they only get a tiny bit of indirect lighting but in the reflections there is quite obvious bit of light shining through that spot for some reason. When camera gets closer, the reflection fades away.

I tried putting box reflections and sphere reflections with various influence sizes. That didn’t change anything. I had sky light before, I deleted it thinking it might have been the cause but it wasn’t.

I did build the lighting and reflection captures over and over again.

Here’s the image of the whole thing: