@Rycaut yeah, i don’t think the browser does that, (or should, indeed), i’m not sure how the referer behaves if the query is from an iframe in the page, so indeed there might be multiple levels of indirection, and yeah, it could also be an extension in your browser.
Heck, it could even be a non-browser application fetching info for programmatic usage.
If you think it might happen again, you could use mitmproxy to capture/monitor all your traffic.