I think you have uploaded the wrong texture/mesh, because it looks like the uv’s are not correct on the mesh that you have uploaded 
let’s try this again, it’s on the answer hub. sorry I hope it works because if it doesn’t then I may be a little bit messed over because the file was removed from my computer. I exported it from the unreal and then sent it.
Rotate the Uv’s 90° and reimport.
Really strange…
somehow I’m still not abel to see the seam that you show on your picture. Download those files and try out if you can see the seam:
Have you already tried to turn off “specular” in your material?
If your talking about the material, that has been done and for some reason a black shadow is cast and a black shadow is seen on the center portion. If your talking about the actual mesh itself I can try it.
that last message was for Sinking, i will give your file a try, just as soon as I find something to download it to. I don’t have photoshop or a sculpting program on my pc, my boss does all of that on his cinteq, ill log in on his mac and get back to you.
Those are just uasset files -> so you just have to drag and drop them into the content folder of your project (probably you will also have to reassign the texture in the material)
my boss is having my send a message, he says whats going on is where the uv map seam joins together on the cylinder is where the problem is. Is there a way to get the uv seams to match up “seamlessly”
I notice this when I was making a set of modular walls. If their UVs were facing different directions the normals would also be read differently, hence causing seams between meshes. Once I rotated my Uvs to all face the same way it stopped. You have a slightly different problem, my first thought was to set the edges to smooth, but clearly that pillar has smooth edges all around. It’s only a guess, but if you were to rotate your uvs the same way the pillar is build (bottom at the bottom, top at the top), you might get less or no seam. Of course this is all theory, but it would be an easy fix. It’s a strange problem, but definitely one of the normals direction.
You might also try to let Unreal compute normals and tangents and see if that comes out better than the import from *.FBX, but I guess you tried that already. I know I did and it never changed a thing anyway ^^
Ultimately what we found was a combination of issues. Primarily the light map needed to be adjusted to create more spacing in between each element, which did help a little but mostly it feels as thou there is really no true way to completely hide the seam on a cylinder. Hiding seams on non cylindrical items is considerably easier since there is usually an area that just makes sense to use but using a combination of rotation and proper lighting helps to make it less noticeable. Truthfully if you were to look at the UV map that contains the gradient colors the issue looks related as the wrap from one side of the seam to the other can have a gradient going from dark green to yellow which is consistent with the tone difference at the seam. If there is something I’m missing that would make it less visible I would be completely open to it…