Export from Blender to Unity

Hello to everyone,

I exported my photogrammetrically created 3D Model in Blender to clean the model edges and there is no problem. After cleaning the model edges, I exported my model consisting of 22 tiles one by one in obj format and imported it one by one into unity. There were deformations on the model surfaces.

How can I solve this problem.

Blender Screenshot

Unity Screenshot

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