born2run (love the name, I'm a runner too), I am having exactly the same issue. My Adsense has gone down by 2/3rds and when I asked Adsense, I was told it was due to 'invalid traffic'. This corresponded with me switching from an old version of Joomla & Duda to a responsive Wordpress site. I understand a my mobile urls all broke etc., but that's been resolved now. Lots of testing, including switching back to a new Joomla & Duda and my AS went back up for a day, but dropped again the following day.

Traffic numbers the same, Adsense say the only 'correct' reporting is Adsense (not Analytics), I don't know how I can go from valid to invalid traffic overnight.

Is your traffic coming from the same part of the world as it was previously? Has your CTR changed (don't tell me what it is, just whether or not it's changed) Are you checking your logfiles, or running something like StatCounter to see if you might be hit by bad bots?

born2run, is your Adsense reduced at the end of the month, so you have your total figure and then they deduct money for invalid traffic, or has your day to day Adsense decreased? The latter has happened to me.

Literally overnight it went down by 2/3rds and they keep saying it's due to invalid traffic, but my traffic has remained the same. So all of a sudden it has become invalid? They said to add more content and spend money on marketing, but this has had a devastating impact on our finances.

I am now earning what I was 8 years ago, but have hundreds more articles and 250% more traffic.

I am now earning what I was 8 years ago, but have hundreds more articles and 250% more traffic.

I don't think that is unusual nowadays.

@born2run
It seems that much of your efforts so far has been focused on identifying and blocking bots. Have you looked at overall traffic patterns in GA and Adsense to see if you see any abnormal activity on specific pages of your site? Have you checked your reports in Adsense to see if any ad units, or creative sizes are outperforming others in terms CTR? An ad-unit that is misplaced on a page or rendered invisible could cause invalid click activity. Have you checked your code?

Adsense is complaining there is invalid traffic not invalid click activity NickMNS..

I don't think that is unusual nowadays.

Maybe not, but for it to drop by 2/3rds overnight? Which incidentally coincided with me switching from Duda mobile and desktop to responsive. The mobile traffic bounced around for a while, but is now settled. They are saying it's a sudden drop in mobile traffic, but Analytics shows mobile/desktop traffic the same as last month, when I was earning 2/3rds more.

I've checked all of the above NickMNS, everything is completely normal.

Last week out of interest I switched back to Duda and my income went back up to normal levels, I thought 'woohoo, solved it', but the following day it went back down again so I turned Duda off.

Adsense is complaining there is invalid traffic not invalid click activity

I understand that it is invalid traffic. But it could be that this traffic is always hitting the same pages. Also it could be that some pages are being requested multiple times due to a coding error or conflict of some type with CF, thus appearing to Adsense as invalid traffic. Whatever the reason, the first thing I would check is for anomalies within analytics and Adsense, this could provide valuable hints as to the source of the problem and it is quick and easy.

NickMNS interesting, you are saying pages could be being requested multiple times coz of conflict with Cloudflare, hence appearing to adsense as invalid traffic. How do I ascertain this? Please assist. Thanks!

Interesting point NickMNS as I have been reading the adsense support comments again and it says following:

"Your earnings were deducted due to the detection of invalid traffic particularly on desktop and tablets and mostly coming from your site example.com."

WTH? How do I solve this issue? Or use GA to figure out the source of the problem?

you are saying pages could be being requested multiple times coz of conflict with Cloudflare

I am speculating, I don't know this. But my point is that when you change environments, bugs could appear that did not show up previously for any of a wide variety of reasons.

I would check in GA the Behaviour -> Publisher Pages report (this assumes that you linked Adsense and Analytics) sort by publisher impressions (the default) and the try sorting by page revenue, and check to see if any pages stand out, pages that typically in the past have not had that much traffic but that are now generating high revenue or unusually high number of impressions.

Also compare Publisher impressions to Publisher monetized page views, if you have three ads per page and you have pages with impressions that are more than a multiple of three you'll know something is wrong.

Using the advanced filter set Publisher Viewable Impressions equal 0% and then sort in descending order page revenue. Theoretically you should not earn anything for an ad that is not viewed, in practice you may find a few ad clicks but if you are seeing a lot, again you will have potentially localized the problem. Typically a when a bot clicks on an ad the ad should not be viewable. Note that the few ad clicks may occur when the user clicks the ad when less than 50% of it is displayed.

Finally, in Behaviour check the Publisher Referrers, and sort by revenue. You will immediately see if any referrers stand out.

Great advice NickMNS.. I shall report back here shortly!

You can also take a look in Analytics by service provider. One of the pinned posts in this forum is a very long one about bots, and it's worth a read. I reduced a lot of issues by blocking a lot of Amazon AWS and some other service provider traffic that just couldn't have been genuine.

Google's all about patterns, so if you wanna go sleuthing, you gotta be all about looking for patterns too.