mondrian3 set by aggregate

Question

Good morning,

i'm trying to implement a set with aggregate function but the following query return null for test [Measures].[tt]

WITH
MEMBER [Periodi].[ROLLING2024] AS
    Aggregate(Filter([Periodi].Members,
[Periodi].CurrentMember.properties('KEY') = "CNV.48"
OR [Periodi].CurrentMember.properties('KEY') = "CNV.47"
OR [Periodi].CurrentMember.properties('KEY') = "CNV.49"))
SET
[~ COLUMNS_Rolling] AS
    {[Periodi].[ROLLING2024]}
MEMBER [Measures].[tt] AS
    --Sum(Descendants([Periodo].CurrentMember,[Periodo].[Giro Visita]), ValidMeasure([Measures].[FFL.DTRATTANTI]))
    Sum(Descendants([Periodi].CurrentMember,[Periodi].[Giro Visita]), ValidMeasure([Measures].[FFL.DTRATTANTI]))
SET
[~ ROWS_Prodotti_Prodotti] AS
    {([Prodotti].[(All)].Members)}
SELECT
    CrossJoin([~ COLUMNS_Rolling],
    {[Measures].[tt]}) ON
    COLUMNS,
    Order([~ ROWS_Prodotti_Prodotti],
    [Prodotti].CURRENTMEMBER.ORDERKEY,
    ASC) ON
    ROWS
FROM
    [DatixStruttura]

if i set
MEMBER [Measures].[tt] AS     **Sum(Descendants([Periodo].CurrentMember,[Periodo].[Giro Visita]), ValidMeasure([Measures].[FFL.DTRATTANTI]))**

it works fine (i create a clone of dimension periodi), it's like calling the set as the same of dimension using in descendant funcion create conflict

the set works fine, so the result of measure tt is not null