Measure with condition based on date slicer

Hello. I'm trying to make a tricky powerbi dax measure and I'm a bit lost right know because it's been 2 days i'm struggling on this. 

I have the following data model in my db:

In my powerbi dashboard, i'm trying to display this data in a table with a date slicer (based on imputation_date) and following these conditions:

1. If my maximum date range is above exceeding_date: i want to display the sum (for each group of agent and task)  of value_after_exceeding
2. Else i want to display the sum of value_before_exceeding
3. In both case, i want the sum for the date range based on date_imputation

I create a table based on min and max imputation_date:

calendar_imputation = CALENDAR(MIN(valo_fact_imputation[date_imputation]), MAX(valo_fact_imputation[date_imputation]))

My test visual look like this:

(visual 1)

(visual 2)

I have mesaures for min and max slicer date:

min_slicer_date = CALCULATE(FIRSTDATE(calendar_imputation[Date]))

max_slicer_date = CALCULATE(LASTDATE(calendar_imputation[Date]))

And so far my measure to calculate date looks like this:

sales = 
VAR grouped_by_filter_date =
SUMMARIZE(
    FILTER(valo_fact_imputation,
        valo_fact_imputation[date_imputation] >= [min_slicer_date] && valo_fact_imputation[date_imputation] <= [max_slicer_date]
    ),
    valo_fact_imputation[task_id],
	valo_fact_imputation[agent],
    "exceeding", CALCULATE(LASTDATE(valo_fact_imputation[exceeding_date]), ALLEXCEPT(valo_fact_imputation, valo_fact_imputation[task_id], valo_fact_imputation[agent]))
)
return CALCULATE(
        IF(
            COUNTAX(grouped_by_filter_date, [exceeding]) > 0,
            SUMX(
                SUMMARIZE(
                    grouped_by_filter_date,
                    valo_fact_imputation[task_id],
                    valo_fact_imputation[agent],
                    "sum_valo_imput", CALCULATE(SUM(valo_fact_imputation[value_after_exceeding]))),
                [sum_valo_imput]
            ),
            SUMX(
                SUMMARIZE(
                    grouped_by_filter_date,
                    valo_fact_imputation[task_id],
                    valo_fact_imputation[agent],
                    "sum_valo_imput", CALCULATE(SUM(valo_fact_imputation[value_before_exceeding]))), 
                [sum_valo_imput]
            )
        )
)

 My problem is that on visual 1, the sum is made on valo_afeter_exceeding even if it looks like there is no value my "exceeding" column from my SUMMARIZE method.

Any help appreciated and don't hesitate to ask for more infos.