Cumulative Sum & Percentage Calculations Without Using Rank Dax

For the formula below, I don't have a column for 'Table'[Date Filled Month Year Sort], what would this entail please?

Cumm Based on Date = CALCULATE(Sum(Table[Booking filled]) , Window(1,ABS,0,REL, Summarize(ALLSELECTED('Table'), Table[Vacancy Month Year], Table[Date Filled Month Year], Table[Date Filled Month Year Sort]),ORDERBY('Table'[Date Filled Month Year Sort],ASC), PARTITIONBY(Table[Vacancy Month Year]) ))

I also tried using Example 2 from here - https://learn.microsoft.com/en-us/dax/window-function-dax but it didn't work with the PARTITIONBY.

I got this working instead but it is not doing a cumulative as shown in the example, possible due to the PARTITIONBY issue.

Filled Rolling Sum = SUMX (WINDOW(1,ABS,0,REL,ALLSELECTED(Table[FilledYear],Table[FilledMonth]),ORDERBY(Table[FilledYear])),Table[Total Bookings Filled New Sum])

 

Filled Year and Filled Month are just extracted from the Date Filled column.

 

The example below is filtered for vacancies received in April. It may have slightly different  to the figures before because I have received new data for August.

 

 

The cumulative sum there is still based on the Ranking system which is not working well.

 

Additionally, I'm not sure why there are "Blank" month/year when the filled date column has a date. These 4 blank entries are for May 2023.

 

I have 2 date tables to display this. The 1st date table is for vacancy received and it has a relationship to the "Vacancy Received" date in the data table and the 2nd date table is for date filled and it has a relationship to the "Date Filled" date in the data table. Am I doing anything wrong to cause these blank entries please?

 

Thanks 🙂