In Strategy Web, users may notice that grids in a Document with a Grand Total will no longer display a grand total the grid is targeted by a selector with the 'Apply selections as a filter' option disabled, as shown:

When the “Apply selections as a filter” selector option is enabled, the grid Grand Total is displayed, as shown:

The aggregation for Grand Totals is only performed when the option for 'Apply selections as a filter' option is enabled.
For further information on the usage of Selectors and the 'Apply selections as a filter' option, refer to the Strategy technical note:KB33423: "Apply selections as filter" option resolves a Grand total display issue but causes additional issues when exporting a dashboard to Flash in MicroStrategy Web 9.4.x