summerize differently depending on filter

I double and triple checked and also created the visual new. But still empty

where 
Jahr = YEAR ('Date'[Date])

Monat = MONTH('Date'[Date])

The code for "Lost_amount3"

Lost_amount3 = VAR __SummaryTable =

    ADDCOLUMNS ( VALUES ( 'Date'[Date].[Monat]), "@value2", [Lost_amount] )

RETURN

    SUMX ( __SummaryTable, [@value2] )

seems to summarize correct for one customer

 

Is it somehow possible to modify this?

Anonymous 

Would you please double check that these are the same columns that are used in the table visual one by one?

Anonymous 

Which table / column represents the costomer?

The customers are coming from a table, that selects column from table

relationships are:

Anonymous 

Please try

Lost_amount3 =
SUMX (
CROSSJOIN ( VALUES ( 'Date'[Monta] ), VALUES ( 'Lost_prep'[Cliento] ) ),
[Lost_amount]
)

Hmmm, now it summarizes, but it has the wrong amount. Lost_amount should be the same as Lost_amount3

Anonymous 
Please try

Lost_amount3 =
SUMX (
    GENERATE (
        SUMMARIZE ( 'Date', 'Date'[Jahr], 'Date'[Monta] ),
        CALCULATETABLE ( VALUES ( 'Lost_prep'[Cliento] ) )
    ),
    [Lost_amount]
)

It summarized too much. So, I thought it would be better with a filter

but even this does not change something. The total still not a summary

Is this a relationship issue?

Anonymous 

Not sure to be honest. Please try

Lost_amount3 =
SUMX (
GENERATE (
SUMMARIZE ( 'Date', 'Date'[Jahr], 'Date'[Monta] ),
CALCULATETABLE ( VALUES ( 'Lost_prep'[Cliento] ) )
),
CALCULATE (
[Lost_amount],
CROSSFILTER ( 'Date'[Date], '2_Abfrage_Orderline'[Date], BOTH )
)
)

Lost_amount3 does not match with Lost_amount. DAX seems to be very complicated

Anonymous 
It is better to connect and have a direct look at the data. Let me know if this is possible perhaps tomorrow noon Dubai time.

Oh this would be so great. How can we connect?