Set on slicer axis with different behaviour than aggregated member of same set in the slicer

This query:

with set a as '([Time].[1997].[Q1] : [Time].[1997].[Q2])'
member Time.x as Aggregate(a,[Measures].[Store Sales])
member Measures.x1 as ([Time].[1997].[Q1],[Measures].[Store Sales])
member Measures.x2 as ([Time].[1997].[Q2],[Measures].[Store Sales])
set products as TopCount(Product.[Product
Name].Members,1,Measures.[Store Sales])
SELECT
NON EMPTY products ON 1,
NON EMPTY

{[Measures].[Store Sales], Measures.x1, Measures.x2} ON 0
FROM [Sales]
– where ([Time].[1997].[Q1] : [Time].[1997].[Q2])
where Time.x


Returns:

Urban Small Eggs
497.42
235.62
261.80


While this:



with set a as '([Time].[1997].[Q1] : [Time].[1997].[Q2])'
member Time.x as Aggregate(a,[Measures].[Store Sales])
member Measures.x1 as ([Time].[1997].[Q1],[Measures].[Store Sales])
member Measures.x2 as ([Time].[1997].[Q2],[Measures].[Store Sales])
set products as TopCount(Product.[Product
Name].Members,1,Measures.[Store Sales])
SELECT
NON EMPTY products ON 1,
NON EMPTY {[Measures].[Store Sales], Measures.x1, Measures.x2}

ON 0
FROM [Sales]
where ([Time].[1997].[Q1] : [Time].[1997].[Q2])
– where Time.x

returns:

Urban Small Eggs
497.42
497.42
497.42

I'd expect the first one to be the correct result