CubeViewGrid.ExpandedRowHeaders.HeaderItems not returning all headers

This is OS v7.4.1
It is running in a Cube View Extender Rule.
I've tried both CubeViewGrid.ExpandedRowHeaders  and CubeViewGrid.AllExpandedRowHeaders 

expandedRowHeaders = cubeViewGrid.AllExpandedRowHeaders;
int rowNum = 0;
StringBuilder sb = new StringBuilder();
foreach(CVGHeader cVGHeader in expandedRowHeaders)
{
   List<CVGHeaderItem> headerItems = cVGHeader.HeaderItems;
   sb.Append($"Row[{++rowNum}]:");
   foreach(CVGHeaderItem cVGHeaderItem in headerItems)
   {
      if(cVGHeaderItem.MemberInfo.NameAndDescription.Length>0)
         sb.Append($"{cVGHeaderItem.MemberInfo.NameAndDescription}|");
   }
   sb.AppendLine();
}

Using cubeViewGrid.ExpandedRowHeaders yeilds :

Using cubeViewGrid.AllExpandedRowHeaders yeilds (ironically none of the nested members on Column2):

I'm not getting the members shown in the green boxes: