I was getting ready to disable stale users to free up licenses when I noticed that there is a huge discrepancy between exported report of licensed users and the license consumption as displayed when I click the License Info dropdown menu. In my case, the dropdown says I'm using more than 21,000 licenses out of 26,000, but when I go to the reports section and export licensed users, it returns just over 15,000 rows. 

FYI, I tried to upload two screenshots, one of the excel report and the other of the dropdown screen, but got an error "unable to process request".