lighting problem with procedurally modified and tiled meshes

I have one directional light and 3D tiled meshes. I modified meshes with perlin noise, change Y coordinates and after RecalculateNormals().

I tried all shaders mobile diffuse, standart, vertexlit etc… Same problem.
I used “40x40 Maya modelled flat plane” or “10x10 Unity Plane”, i have same problem with both of them.
Also tried flat plane model import settings normal & tangent to calculate. I tried to smooth edges in Maya. Same…

My problem is lighting on hills, their shadows not contuine on neigbour mesh, I can tell every meshes has it own lighting algortihm, they are not working / computing together.

I tried to CombineMeshes, combined mesh has same problem too.

I stucked here, any help would be nice and save my other one week maybe…

I used this tutorial and codes.

Forward Rendering, Infinite World, One Directional Light, No baking or light maps

Thank you all

I found my problem. It’s %100 about normals. After manipulating vertices, i use RecalculateNormals. and then this problem come.

I used alternative NormalSolver script, found in unity answers. Not worked.

I confirm that i cant recalculate normals proper way.

Cause i exported my created mesh to FBX. Then i reimport it, i see problem shadows again. Then i go models import settings and Set normal import to Calculate, then unity calculated and problem solved.

What can i do now? Why import settings Normal calculation different from RecalculateNormal function? How i can create meshes and manipulate them on fly? Can i change normals as i do vertices?