The ListSourceRowIndex1 and ListSourceRowIndex2 properties have valid values if the CustomFieldSort event fires to compare raw rows in the underlying data source, that is, when the SortLocation property has the DevExpress.Xpf.PivotGrid.FieldSortLocation.Pivot value.
If the CustomFieldSort event fires to compare unique filter values in the Filter Dropdown, the ListSourceRowIndex1 and ListSourceRowIndex2 properties are set to -1.
For more information, refer to the platform-specific events: