Light getting through "gap" between two halfs of the same mesh. PLEASE HELP

Hello all.

I have been working on a mesh that I have had to split into two halves, but somehow UE4 thinks there is a gap between them. I don’t see how this is possible, as the border between them is comprised of the same vertices (duplicates of the same vertices, but I digress).

The first picture is from below the meshes, and the second is the same from above. As you can see, even though there isn’t a gap between the meshes but ue4 treats it as if there is.

I have tried to split the mesh in both blender and meshmixer but have come across the same problem.

I have also tried to make sure the vertex normals match the original uncut mesh using both blender and meshlab, but again the problem remains.

Any help or ideas on how to fix this would be very much appreciated as I feel very stuck on how to move forward from here!

Why do you care? THe Shadow isn’t visible anyway

You could try enabling “Shadow Two Sided” in the static Mesh details