Blender 2.8 exports fbx with flipped normals export model from blender 2.8 to UE4-> normals are flipped in ue4. Gotta actually flip the normals in blender for it to come right in ue4. this never happened before.
I use the daily 2.8 build (25.3 as for writing  IDEAS?
Check Face Orientation in the Overlays popover:



In my opinion, in the 2.80 it's harder to recognize a inverted normals in default shading.

Also check, that your object doesn't have negative scale. 

Edit: The negative scale can be a byproduct of mirroring (Crtl M) while in object mode. To combat this, mirror the object while in edit mode, and then flip the normals of the mirrored part. Recalculating Normals works just as well.