Flow Detail Barchart not sum over Attributes

[alex-rind]

Example: Flow of People from one country to another; Sex as attribute
Austria; Germany; 2018; 20; Europe; Europe; female
Austria; Germany; 2018; 12; Europe; Europe; male

The bar chart shows bars for 1 attribute value (e.g. 20) but not the sum (e.g. 32).