I have a data set and had grouped the columns and everything was working fine.
I have since refreshed the data and some rows are returning "null" values in 3 of the columns.
I know that it isn't formatting or the data refresh as some rows are working perfectly.
What I am looking at is the total weight loss of a patient in a month where they have been weighed multiple times.
I have added a custom column to pick up the date of weigh in to be "date.start of month" so that when grouping, for June for example, it will pick up everything from within June as I am grouping by the custom column.
When I have refreshed the data, all the months to June work for some patients. i.e. the grouping has worked for January through to May. But when we get to June, it starts returning a "null" in 3 of the grouped by columns (one of which is a sum of the total weight change).
However, for some patients, everything is working absolutely fine even for the new data and we are getting perfect data even in June. As such, I know it isn't the way the date is formatted for example.
I am perplexed as to why just some patients are returning a "null" value in 3 of the columns when previous months data for that patient is fine and other patients are working fully fine across every month.
Desperately needing help as was supposed to have this finalised today!
