Weird merging issue in BO XI 3.1 SP5

SP3 FP5.3

Create a report that contains 3 objects: Country, Year, Revenue

Add table with expression

=Sum(If([Year] Between ("FY2004";"FY2006"); [Revenue]; 0))

Add section by Country

Everything looks nice

Now add new query with only Year.

Now the expression produces null result. But why???

To see the numbers again, you can either unmerge Year (which is usually not an option)

or enable Extend merged dimension values

It is still not clear why this helps.