What can be the cause of this (wrong total stacked bar chart)

[curiousfellow]

Please have a look at this bar chart.

On the tab "Expressions"  I have enabled "Values on datapoints" and on "Presentation" I enabled "Still show total on Top".  Most of the displayed totals are correct but not all. 

In the wrong subtotal there are no duplicate values counted.wrong total 

[albertovarela]

This happens when you have both negative and positive stack areas in the same bar.  The negative values get plotted to the left of the reference line (zero) and the positives to the right.  This is very confusing as the length of the bar does not represent its total value. 

[curiousfellow]

It is confusing indeed, but I still don't understand why a wrong number (25) is shown while other totals are correct.

[marcus_sommer]

Not all others are correct. Two bars above the value should be -5 instead of 5. I think like Alberto hinted that this is confusing but it worked like designed and means it results for positive and negative values a total. I doubt that there are ways to adjust this kind of chart-type.

An alternatively may be to remove your second stacked dimension and to calculate everything with expressions. This means here you need 3 expressions - one for each sub-dimension and a the third is just to display the total. Here a very basic example with a few records and two dimensions F1 & F2 and a measure V. Essential here is to set an offset value and a transparent colour to the third bar (whereby you may play a bit with it to find more suitable results for your visualization):

- Marcus

[curiousfellow]

Thank you both for your explanation. I am aware of the alternative as suggested by Marcus. In this case however it is not possible to get the (real) total next to the bar when values are negative and positive.

Turns out hat both values have to be or positive or negative.  Using the "Still show total on Top"  is a dangerous feature to use then.