What would be causing this concrete blend material to become darker?

[FrankGehry]

I created a blend material for a concrete texture, and I applied a dirt texture to the blend in order to allow some occlusion to occur on the edges (so they appear a bit darker). A weird phenomenon is happening where on two smaller panels of the component, it appears the occlusion is occurring on the entire panel—not just the edges.

Does anyone have any idea what could be causing this? I cannot render this because the result would be so visually jarring.

[kenancakir]

Apply edge texture to the map section.. As i remember it helps..

[FrankGehry]

Apply edge texture to the map section.. As i remember it helps..

Thank you for your input!

I do have an edge texture applied to one of the map inputs. It's a rather simple grunge texture so the occlusion isn't just a fade. I tried adding the same texture to other map input, but this just made the occlusion effect go away altogether.

[kenancakir]

Your unocluded color is black, the main texture should be add there.. Add a color correction texture to the occluded color map area and add your main texture to the map area into the color correction.. Play with brightness and contrast to make it darker.. That is it..İnvert normals means outer edges are going to be darker, set it off for ambient occlusion effect.. Self occlusion only means other surfaces will not affect the wall and i suggest you to set it off too..