To shut down an indicator, one has to remove it from the chart. At that, its drawing and recalculation of its values will stop. To remove an indicator from the chart, one has to execute its context menu commands of "Delete Indicator" or "Delete Indicator Window", or the chart context menu command of "Indicators List — Delete".
Attention: Removing of a custom indicator from the "Navigator" window will not shut down the indicator of the same name imposed in the chart.