Could Get Correct value in Previous Month KPI

[Pooja_QlikSense28]

I have two Kpi's which displays 

1. current month outstanding in USD

Chart Expression: 

Sum({<LinkDate={">=$(MonthStart)<=($(vmaxdate))"}>}[Amount USD])/1000

Variables:

1. vmaxdate :   

=max(LinkDate)

2. MonthStart:

= Num(MonthStart($(vmaxdate)))

2. previous month outstanding in USD

Chart Expression: 

Sum({<LinkDate={">=$(vPreviousMonthStart)<=($(vPreviousMonthEnd))"}>}[Amount USD])/1000

Variables:

1.vPreviousMonthStart:

=num(MonthStart(AddMonths($(vmaxdate),-1)))

2.vPreviousMonthEnd:

=num(MonthEnd(AddMonths($(vmaxdate),-1)))

ISSUE:

My calculation is correct for current month and i am getting desired results also i am able to get correct previous month start and end but my sum is incorrect and when select a month from filter then i get same value in both KPI 

[Anil_Babu_Samineni]

@Pooja_QlikSense28 Hope your variable returns correct? For me this sounds you are comparing data with Date vs Number format.