Weird Lighting Glitches

Hi how’s it going everyone? I’m working on a small environment, and I still can’t figure out what is causing these weird lighting issues. It happens on meshes and objects that have materials applied to them, but also happens to meshes without any materials applied (using basic blockout checkered material). It looks as if the objects are glazed or something, and on the cobblestone for example it just completely blows it out and makes it look horrible. I would really appreciate if someone could shed some light on what might be causing this and what I can do to fix it.

PS. All roughness maps are set to grayscale linear sRGB turned off, and they are more on the matte side (values ranging from around 0.65 - 0.9).
I am also using UE 4.10.4 with VXGI and HBAO+ (had the exact same result with default 4.10.4 no VXGI or HBAO+) with a GTX 970.

Thanks in advance!

Looks like somebody set their roughness to 0! 0 Roughness is extremely sharp and extremely bright: typically, I never go lower than 0.1, and I try to stay between 0.1 and 0.2 for most sharp surfaces to prevent the odd lighting.