Sorry, should’ve been more specific. This isn’t an Unreal problem, it’s how it was built in Blender. (Should’ve been more specific, but it was late and I was tired.)
The first image I’ve attached shows two cubes with backface culling activated (it’s off by default). The one on the left has it’s face normals facing outwards, the one on the right has them facing inwards (much like the model you posted above). I’ve also included the areas of the properties region of the 3d viewport (n key menu) to show how to display these.
The second shows ‘a’ method to fix the problem (could also use ‘flip normals’ option also shown in the image).
Sorry it’s not a video, but hope it helps just the same. You could also do a youtube search for ‘Blender reversed normals’ or something of the like.
