Tiled landscape material problem

Hello everyone!

I have a quick question. Recently, I have started building my landscape inside World Machine and I have exported the tiled landscape followed with color map, flow map, ambient occlusion and all kind of different and useful textures separately. Then, I combine them all together within photoshop and import inside UE.
However, when I create the material I am getting this strange artifact at the place where two tiled components are getting connected.

Any suggestions on that?