Hello there @El_Old_Coyote!
At first glance, that looks like a misplaced section of a UV map, touching the very edge of that seam. So, the first step would be to make sure that your edges are not overlapping in the affected UVs.
After that, we have the usual shenanigans between Unreal and Blender, they just don’t have the best relation. I would test resetting import/export settings in both platforms, then transfer your assets again.
For further methods to test, please check the related scenario below: