Carrying on from my previous question  here  
I still do not understand why pbi desktop table visual not giving the same result as per daxstudio.

Replicated test

--  parent - child rollup test
--  3 rows, 3 values, sumx
EVALUATE
--RollupTest = 
DATATABLE (
    "name", STRING,
    "child value", INTEGER,
    {
        { "test1", 1 },
        { "test2", 3 },
        { "test3", 1 } 
    }
)



EVALUATE
--rollup test =
VAR _rollup =
    SUMX (
        CALCULATETABLE (
            'RollupTest'
        ),
    'RollupTest'[child value]
    )
RETURN
    { _rollup }

Daxstudio

Yep, we get 5  (1+3+1)  correct

PBI Desktop

Nope, the  [rollup test]  column does not return 5 for each of the 3 rows.  Why?

No doubt there is a missunderstanding in my “row context” knowledge.  But to me the [rollup test] calculated column clearly states:

1. hit the entire ‘rollup test’ table again for each row

2. sum that temporary table

Which gives result of 5 for each of the 3 row iterations.  Does it not?

This question posted in pbi community link