There is a line in the data anomalies support page of Google that was recently posted about an “update to web search logs analysis” when showing the Search Analytics report in the Google Search Console. This update to the support page was made on December 14 and it looks like it’s going to impact just websites. Google said that “this change may increase the total number of clicks and impressions.”
By checking out your Google Search Analytics report in the Google Search Console, you’ll notice a vertical update line on the December 14 data. This line links to this update in the data anomalies page.
Is this related to the app install button change? Zineb Ait Bahajii told Barry Schwartz from Search Engine Land that it was unrealted. She said that Google is “logging data differently,” and has the possibility of of impacting the reports seen in the Google Search Console.