Basic Unique Visitor question
At the company, we are connecting PowerBi with Adobe. Our numbers (Adobe vs BPI) were different for the same metrics and time period. However, we realized that if we added up manually each day of the month for unique visitors (just an example), the total was different than what Adobe is showing as the total. Is there an explanation for this? Am I missing something elemental about it?

Here we are getting total unique visitors as 50 but adding all the rows the real total is 82.
What am I missing here?