Previous month don't working on a Bar Chart

[BrenoSater]

Hi Team!

I'm new at QlikSense and i have a doubt.

i have a measure that brings me the value of a previous month 

COUNT({<ClassificatorField={"A", "B"}, AnotherClassifier={"Yes"}, PERIOD={"$(=MaxString(AddMonths(PERIOD,-1)))"}>} PERIOD)

And works perfectly...

But when i put on a Bar Chart, he returns only the previous month value...

I would like it to show me the month by month on the X axis and on the Y axis the value of the previous month...

Help?

Thanks!