2 Variables with different syntax and 2 different results (expecting the same)

Hi,

I can't understand why I don't have the same result for 2 variables, the syntax is different but the logic behind is the same ... If you could help please.

Dimensions: [Months](yyyy/MM) and [Id company]

Measure: [Quantity]

- 1st variable:

=Count(If([Month] InList ("2018/10";"2018/11") And [Quantity]>0;[Id company]))

With this variable I get the right result

- 2nd variable:

=Count([Id company] Where [Month] InList ("2018/10";"2018/11") And [Quantity]>0)

With this variable I get a wrong result (I get 0 ...)

Why I don't get the same number? It seems the same logic to me..

Thank you guys for helping me