Weird seams on modular environment

Hi, I built a simple testing modular environment to test some things on Unity. It consists just in three pieces to check how it fit toghether. The set in Maya looks good but once I import it into unity I see weird seems between the pieces.

Here is a comparison between how it looks on Maya and Unity:

I modified the UV map to avoid edges of the texture and tried all the posibilities under texture properties on unity but none of these steps solved the issue.

Here you can see another screenshot from another angle of my scene:

Any idea why is this happening and how to solve it?

Regards,