Alembic cache doesn't display lighting correctly on TwoSided backfaces
If you have a face with backwards normals in an alembic cache animation, applying a material with the TwoSided flag on it does not correctly display the backfaces.
It works correctly when the same file is imported as static and skeletal. On the underside of the cache geometry it is lit how the top should be.
Attached is this example project for 4.18 with the alembic file and source blender file. Also happens on 4.19 prev 6.
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