Sorting changes when selection made

[Gang]

Hi ,

I Created a Month filed by using the expression in script

"Pick(Right(RptMonth,2) , 'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec') AS Mntname" and the another filed as RptMonth it has a data like 202007. Now my question are I need to create a chart it has to static even when selection made.

The below expression helps me to achieve it  

Match(only({1}Mntname),'Jan','Feb','Mar','Apr','May','Jun','Jul','Aug','Sep','Oct','Nov','Dec')

But i created an another expression by using dual function but its not static  when selection made.

Dual(only({1}Mntname),right(RptMonth,2))

Could anyone helps me to understand why ?

Thanks

[tm_burgers · Accepted solution]

I can't particularly explain why - but I would suggest reworking your load script to create the month as a datefield

something like - 

makedate(left(RptMonth,4),right(RptMonth,2)) as RptMonth 

then this will get picked up by the autoCalendar function - and then you can use the autoCalendar Month. 

RptMonth.autoCalendar.Month in your visualization - which should ensure that the sorting is 👍