Problem importing meshes

hi im importing a kitchen using datasmith and i have a problem with some doors when i open it on unreal doesn´t appers the face that i fix with 2 faces on maetrial but looking density light map it appears black and if build the light the color looks different than the other meshes that don´t have this issue

here you can see… the first highfurniture and all the bottom need 1 face if i active on the material when i build the light, shows like a mirror