I had a similar question up yesterday. I have an app with a Pivot table that divides cases into ages. However when i collapse the table the sums does not add up?!? Naturally I would like the totals to add up on each row. i would like the individual ages to be added up as well. I have also noticed that if there are mote than one row on the same instance then the total does not add up.
You shouldn't be using aggr() like that in your expressions. Group and Name are already dimensions on the chart, so aggr() isn't needed. Take it off of your expressions, and it should work like you expect it to.