Baking issue, curvature problem

Hello, i am tring to create a stylized material pipeline on painter. For trial, i just unwrapped, triangulated and exported this ready modeled teapot as .fbx. When i assign smart materials or apply mask editor with fill layers on teapot, this problem appears on model.
When i triangulate the model, there is stretching on uv islands almost everywhere.
I click “compute tangent space per fragment” when importing the .fbx.
How do i solve this issue? Thanks a lot!