Summarize with ALL

Hello everyone,

I have the following function:

YEAR | MAX =
VAR vals = 
                SUMMARIZE(
                 'Date' ,
                 'Date'[Year],
                 "myMeasure", CALCULATE([Prod | Max | AllY],  ALL('Date'))
               )
    VAR measureMax = MAXX(vals, [myMeasure])
    VAR y_value = calculate(MAXX(FILTER(vals, [myMeasure] = measureMax), 'Date'[Year]))
RETURN
    y_value

The measure [Prod | Max | AllY] is:

calculate(MAXX(BD,BD[Production]), ALL('Date'[Year]))

Both tables (BD and Date) are connected via Date[Date] -> BD[Date] in a 1-to-many relationship both directions.

I checked the var measureMax and its working properly. 

The var y_value is however, wrong! Its returning the year as if the ALL function wasn't there.

I tried different approaches (like addcolumns and so on) but with no success.

What am I missing?

Thank you.