There are often complaints that the Google AdSense reports do not match up with third-party tracking software. In reality, there are complaints that they don't even match up with Google's own tracking software, Google Analytics.
In a Google AdSense Help thread Google AdSense Engineer, Guillaume, responded to complaints on third party tracking and serving software reports different numbers than that is reported in the Google AdSense console.
Guillaume said, "Third-party click counter are often not accurate, and could even negatively impact your earnings due to latency increase and interference with AdSense."
You got that, he said, not only are third-party counters "not accurate" but even more so, they can reduce your AdSense earnings. He goes on to explain why.
For instance, it is difficult for third-party click counters to exclude clicks where the user interrupts the loading of the advertiser page.
Please note that third-party click counters can only but over-estimate click counts, since they don't know about invalid clicks . So if you think that something is not right, I'd recommend stopping paying attention to the misleading information provided by third-party click counters.
So you'd have to assume that using Google's own tracking and ad serving technology would match pretty closely. So using Google Analytics and Google Ad Manager, now known as "DoubleClick for Publishers" would match virtually exactly, but they never do.
Forum discussion at Google AdSense Help.