Drill down into a bar on a stacked bar graph changes the per bar counting method

Drill down into a bar on a stacked bar graph changes the per bar counting method

When I drill down into a bar on a stacked bar type graph then the bar counts on the resulting graph do change to "adding style". What I mean with "adding style" is that each consequent bar on the resulting graph does display the total value of the former (the ones to the left) bar values plus its self value. This problem only happens on the drill down graphs but not on the main report. Please check the following sample. Is there a way to fix this issue ?