Report Writer - Not display quantity value when using Period as variation

Dear SAP experts,

I'm working on Report writer for Overhead cost. I create report using CCSS table, then in report I design SWKG key figure for Total Cost and EMBGI key figure for Actual Qty posted. In my report, I maintain Period as general selection which is from 1 to 12.

My problem is that when I do not use Period characteristic as Variation, report display both Total Cost and Actual Qty posted value. But when I use Period characteristic as Variation, report display only Total Cost value.

I want to use period as Variation in my report. I have searched for sap note about error in variation for report painter, but I have not find any solution.

Are there anyone in the same problem with me? I really appreciate to hear your advices.

Thanks advance for you help,

Regards.