I have a sample workbook here with two connections.
Jan-April: Has data Jan- April (must be secondary connection)
Jan-Mar: Has data Jan-Mar (Primary Connection)
The "Jan-Mar" connection needs to be the primary connection. When I make a grand total calculation broken down by month I get 21 (total Jan-Mar) however when I view this calculation at the year level I get 28 (total Jan-April).