How to sum a column disregarding repeated IDs

You could try to create a rownumber per group (ID CHURN) using the following usefull blogpost by Radacad:

https://radacad.com/create-row-number-for-each-group-in-power-bi-using-power-query

You would then get a column with a rownumber per ID CHURN value. 
Like so:
IDCHURN   row

22                1

22                2

23                 1

24                 1

24                 2

The last step would be to filter the Row column to value = 1 using the user interface. This would leave only one row per IDCHURN.

Another option would be to remove the column Churn reason and then click on the remove duplicates option. For a how-to see : https://excelchamps.com/power-query/remove-duplicates/

Hope this helps!