Strange artefacts on a mesh UE 4.19

Community Community & Industry Discussion
1

I cant seem to figure the reason for dark spots on this rather simple mesh.
Please see the attached max and fbx file.

HighresScreenshot00000.jpg
HighresScreenshot00000.jpg1775×832 76.5 KB

  1. I have tried different lightmap resolutions and layout without any significant effect.
  2. Detaching the Outer most element from the Object removes the “shades” from it. So apparently this may have something to do With smoothing Groups.
  3. I have tested various smoothing groups on the mesh but the shades are still there.
  4. The provide FBX has a lightmap resolution for 512. Baking this with 64 gives a better result for some reason??

Please advice if you have encountered a similar problem.

Cheers