Table that shows Select Month Variance- NOT WORKING

[Noor51]

I trying to create a table in Qlik sense so that when you select a month it show the select month sales and pervious month sale and variance for each manufacturer.  The only part that not working is the pervious month sales (Jan - 2023). I would appreciate any help with this problem.   

Attach is the table with the set expression that I have used. 

FYI - I thought it could be my date formatting, but I ruled that out after a lot analysis.

Set Expression	[Global Manufacturer]	SUM({<[Calendar Year/Month]={$(=AddMonths(date#('$(vMonthSelect),-1')))}>} [Sales in Units])	SUM({<Month={'$(vMonthSelect)'}>} [Sales in Units])	SUM({<Month={'$(vMonthSelect)'}>} [Sales in Units])-SUM({<[Calendar Year/Month]={$(=AddMonths(date#('$(vMonthSelect),-1')))}>} [Sales in Units])
	Global Manufacturer	Jan-2023	Feb-23	Variance from Prior Month
	A	0	40,539,232	40,539,232
	B	0	27,008,603	27,008,603
	C	0	23,578,479	23,578,479
	D	0	21,628,491	21,628,491
	E	0	17,721,264	17,721,264
	F	0	17,333,169	17,333,169

[Noor51 · Accepted solution]

I'm using Qlik sense for this for this table. I tired your code and its still the same outcome for pervious month.