Typically, the eCPM and revenue reported by the network is correct. If there is a large discrepancy between the two figures, these troubleshooting steps may help:
If you don’t have auto-CPM enabled already, review the page on auto-CPM.
You should ensure that the waterfall uses the most accurate CPM. This makes your MAX revenue estimates more accurate, and prioritizes your waterfall towards the highest paying network so you make more money.