Imported Blender Tri's have holes in Unreal

Hello, why does my mesh have holes in unreal? Is it because of the tri-count? Is this Unreal re-triangulating my already triangulated mesh therefore creating these holes?
UPDATE: When I export as .obj from Blender to Unreal it creates holes. However when I export as .fbx it seems to fix issue. Otherwise, is there another fix for .obj’s just incase?