I’ll use Google as an example (because of the significance of the large difference in numbers), but the same applies to Bing, Yahoo and probably others.
We usually receive between 1000 and 1500 hits from Google (search engine visits) a day and this is also reflected in our Google Webmaster stats, but from the 16th (of June) onwards Piwik only reports about 5 to 20 hits from Google (search engine visits).
Our Google Webmaster stats show no decrease in traffic (all days from the 16th to the 22nd are in there, with stats that are no different from the days before that) and our own visitor counter also doesn’t show any decrease in traffic. These indications point towards either Google all search engines (Bing and Yahoo are also affected, the others have too low averages to make any statement about them) or Piwik being the problem. The most likely of the two being Piwik (or some configuration).
This problem did not coincide with any upgrade we made, we upgraded to 1.4 relatively soon (< a week) after it was released and we upgrade to 1.5 on the 22nd of June.
Is there anyone experiencing a similar problem or who has an idea as to what might be causing it?
Thanks in advance!