Problem with granularity

Hey mlsx4 ,
glad to hear.
I will try to leave you an understandable description here.
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1. I created a calculated column in "real rate" table (my fact table) to fetch theoretical rates.
Result:

Formula:

LookUp_Theo_rate = 
   LOOKUPVALUE(
      'Theo rate Table'[Theor. Rate], 'Theo rate Table'[YearMonth], 'REAL rate Table'[YearMonth],
      'Theo rate Table'[Code], 'REAL rate Table'[Code],
      'Theo rate Table'[Category], 'REAL rate Table'[Category])

 
Can you pls try to achieve similar result.

When I drop these 2 fields into my table it looks like this:

2. To fill the gaps I used this formula:

Last non blank Theo_rate = 
VAR Last_non_blank_date = 
        CALCULATE(
            MAX('REAL rate Table'[YearMonth]),
            FILTER(
                ALL('REAL rate Table'), 'REAL rate Table'[YearMonth] <= MAX('REAL rate 
                Table'[YearMonth]) && 'REAL rate Table'[LookUp_Theo_rate] <> BLANK() )
            )    //this part will give you the MAX non blank date

VAR Last_non_blank_Value =
        CALCULATE(
            SUM('REAL rate Table'[LookUp_Theo_rate]),
            FILTER(
                ALL('REAL rate Table'), 'REAL rate Table'[YearMonth] = Last_non_blank_date), 
            FILTER(
                ALL('REAL rate Table'), 'REAL rate Table'[Code] = SELECTEDVALUE('REAL rate Table'[Code])),
            'REAL rate Table'[Category] = SELECTEDVALUE('REAL rate Table'[Category])
            )

RETURN
    IF(
        HASONEVALUE('Calendar'[Date]) &&
        [Theor_] <> BLANK(),
        [Theor_],
        Last_non_blank_Value)

Try to apply this piece of code into your model.
I cross my fingers.

I hope I could transfer this well to your case.
This formula gave me this result:

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Regards