is it a custom mesh? did you check the uvs? it looks like you simply didn't unfold this face and therefore it's stretching one line of pixels over the whole face
Also, what does that geometry look like? If that's one really long triangle it's possible that on export the triangulation got flipped from what you were seeing in your modelling program, which could end up screwing your UVs.
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Yes its a static mesh, i checked the UV and nothing unfold there, i also try to change the triangulation and it just change the stretching direction.