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I have some, unintenational, displace on the edges of my mesh

Hello,

For a personal project, i have to make an arc made with bricks and also with some breaks on It. Like this image

And for this, i made my mesh on Maya and i imported It in Zbrush to sculpt the breaks in order to export a DisplaceMap for the my scene.
But my problem is that I don’t sculpt or do something with the edges of my mesh however Zbrush Keep putting Displace on It.
For the exemple i plugged it in color
image
image
image

Even when i’m exporting normal, it does the same thing.
image

I’m searching for a solution for my problem, but i’m running out of ideas. So if you have any advices, I will be very happy to hear your advices.

Thanks for the reading !