joined:Aug 30, 2019
and nobody know why
In fact, the system claims it's from "invalid clicks". What "humans" might not know, is why there are invalid clicks, which is a different question.
Now, as I said at another topic, this shouldn't be a problem, because if someone taps an ad, on purpose, he'll confirm his wish to visit the advertiser's page.
By the way, there is no real answer to your question, just common, basic things. I am sure you already checked, but there is nothing to loose reminding them :
- misleading ad placement, visitors thinking the ad is part of the navigation,
- too large ads, on mobile device, if there is no place to put your finger, to scroll the page, it's easy to accidentally tap an ad,
- page layout shifting, elements which are loaded asynchronously (ads, images, dynamically injected DOM, etc...) can produce a reflow of the page layout, which can lead to tap an element which was not there the fraction of second before,
- block bot activities, as much as you can, this involves identifying suspect requests, and blocking Server farms IP ranges,