In the screen shot I have an image I rendered in Blender 2.80 beta. In the second shot, I loaded my project in Blender 2.80 release (via Steam) and now the reflections from my mirrored walls are being distorted. I’m using Principled BSDF shader for the walls set to white, full metallic… while trying to figure out the issue I also set Specular to 1.0. I’m trying to get my floor reflections flat again.
What I’m trying to work back to is the upper image. The floors in the reflections are flat, the pillars are straight up and down. In the second image you can see the floors are bulging up. It’s like the mirrors are bent, in reality, they are totally flat.
Might have been bent normals on the walls, that is the geometry data might have gotten messed up somehow. Normals would indeed affect the reflections off of the surface, so at least it is certainly plausible.