Static mesh's material slot's cast shadow does not require a build of StaticLight

void FMeshSectionSettingsLayout::OnSectionCastShadowChanged
{
...
-  CallPostEditChange();
+ CallPostEditChange(Property);
}

void UStaticMesh::PostEditChangeProperty(FPropertyChangedEvent& PropertyChangedEvent)
{
...
	// Only unbuild lighting for properties which affect static lighting
	if (PropertyName == GET_MEMBER_NAME_CHECKED(UStaticMesh, LightMapResolution)
	|| PropertyName == GET_MEMBER_NAME_CHECKED(UStaticMesh, LightMapCoordinateIndex)
+      || PropertyName == GET_MEMBER_NAME_CHECKED(UStaticMesh, SectionInfoMap))
	{

...

}