clear all slicer selection

Here is my experience:

Below bar chart is my slicer.  If I select all choices, all 4 quarters appear in bar chart, as expected:

All QtrsSurprisingly the same happens when none is selected:No Qtrs We know that when we select 1 Qtr only, such as this, then only one Qtr shows:1 Qtr 
When I toggle the Q1 button (being the only one selected), so that nothing is selected, the bar chart shows all data - all 4 Qtrs (& blank), as in the second example above. 
If several boxes are selected, for example Q1 & Q2 & Q3  in slicer, I first click just one of the selected boxes, e.g., Q3,  The bar chart shows just the Q3 data.  Then I click on Q3 again, deselecting it, and thus all Qtrs are deselected.  The result is in  visualizations is as if all slicer boxes were selected, as in "No Qtrs" screen shot above.