They stopped linking search results directly to the webpages. You have no Google search referrer headers in your logs/analytics any more. When the SERP loads,

They stopped linking search results directly to the webpages. You have no Google search referrer headers in your logs/analytics any more. When the SERP loads, all the results link to the real webpages, so that you see their address in the browser status bar when hovering over a link. Clicking any result link triggers a script that replaces the URL with https://google.com/url?url=the_real_webpage_url https://google.com/url?url=the_real_webpage_url. When you click through, you're clicking a link from google.com to another link on google.com, which redirects to the webpage you intended to visit. The referrer the webpage sees is the intermediate google.com/url page, instead of the search result page. This prevents websites from getting search term data from the SERP URL, if it was present, by removing that URL from referrer headers entirely.