Using the TOTALMTD function but only on business days

Hi guys,

I am trying to create a measure that allows me to accumulate the sales for the month, so I am using the TOTALMTD function, this works correctly on the filtered month (September).

I also want to get the previous month (August), so I add the filter DATEADD(CALENDARIO[Date],-1,month) , however the value is repeated when it is NOT a weekday in August but it is a weekday in September .

I have a calendar table with business days and related to the sales table through dates.

Example:

expectation:

My measures:

TOTALMTD (sep) =