Koen Verbeeck takes us through some unexpected results with the SUMX() function:
Hold on, the result is different for the 29th than the 28th? This is what the title means with incorrect (or unexpected) results. Even though the data looks exactly the same in the table, the result are not.
It is not a bug in the DAX formula language. The problem resides with the duplicates in the table.
Read on to understand what this means and how you can change your code to prevent this issue.