Falmer Shield should have DLC1ArmorMaterielFalmerHeavyOriginal keyword.
1 comment(s) [Closed]
The other (non-heavy) pieces don't have the ArmorMaterialFalmer keyword, just DLC1ArmorMaterielFalmerHeavyOriginal. Dawnguard.esm removed ArmorMaterialFalmer and replaced it with DLC1ArmorMaterialFalmerHeavyOriginal on other "original" pieces, so this was a bug that the shield didn't.
Bethesda also forgot the ArmorHeavy keyword on the shield.