Bug on imported FBX Mesh

Hello, i don’t know how to name this problem but, here i explain it. So i recently imported on UE4 meshes of a Toro model (japanese garden lamp) which i exported to FBX from Blender. Everything looks fine except one of the meshes, the “roof”, which looks weird…
It looks “empty” when you’re looking at it, but when you move the camera in it, it looks normal and full.
It’s really weird because in Blender it looks normal, and all other meshes are imported correctly. (they are all from the same 3d model)

I really need help, thx in advance

(you can click on the picture to see the legend of the pictures and get more infos)