I'm trying to implement the filter option through SenseUI Slider extension. Other than Slider, I'm implementing a drop down and on selecting a value from the dropdown, the filter should be applied. But for some reason, the filter gets applied and then clears off automatically. When I click on the "step back " button on the left top corner of Qlik sense Desktop , the option that I selected from the drop down is getting applied. For some reason, the filter option is not getting applied when I select from the drop down.
This is the code that I use
vars.this.backendApi.selectValues(1, chcZoneFilterVal, true);
where chcZoneFilterVal has value : 
Please find below the screenshot.
I tried with the below option and it worked. But I'm still getting an error message.
Line 1: vars.this.backendApi.selectValues(1, chcZoneFilterVal, false);
Line 2: vars.this.selectValues(1, chcZoneFilterVal, true);
Error message in Line 2:
Uncaught TypeError: Cannot read property '1' of undefined
Please advise me on the same as this is a showstopper for our project. Any help is appreciated.