Custom Report Row Values Don't Equal the Displayed Total
I have a questions that is causing a lot of confusion within my organization. We use Custom Reports to look at distributions of our users based on a particular dimension (in this case device type). But we've experienced discrepancies between the Total and if you actually sum the values the table. For example (please see screenshot below),the total at the top says 317,761. But if you add the 3 values in the table, I get 317,178. That's a 600 user different. We've seen this same problem in varying degrees with other custom reports. Why would this happen? I'm so confused!
Note: the date range is Jan, 1 2017 to July 7, 2017 (if that matters)