Filter and Allexcept

Hello everyone,

I have  classic calendar and sales tables in my model (1 to many related with the shared column "Date").

Do you have any ideas why : 

[Measure1] = CALCULATE( Sum(Sales[Quantity] , FILTER(ALLEXCEPT(Calendar;Calendrar[Year]) , Calendar[Month] = 3))

and

[Measure2] = CALCULATE( Sum(Sales[Quantity] , FILTER(ALL(Calendar) , Calendar[Month] = 3))

return the same result ? - even when the user selects a year with a slicer (from Calendar table of course).

For example when the user selects 2014 with Calendar Slicer, I would expect [Measure1] to compute the sum of quantity for 2014andmonth number 3, whereas it computes the sum of quantity for month number 3 of all the years in the model...

It seems like ALLEXCEPT works as an ALL when it is used as a table argument in a FILTER. Anyone can explain ?

Thanks in advance

I am using Power Pivot in Excel 2016.