Ad comes from the ad-server, but is routed over the current domain

[rcjordan]

^{We've touched on this trick in a previous thread. I ran across more detail while researching userscripts.}

"a technique that is currently being widely deployed to stop domain based adblockers (such as adblockplus, ublockorigin and many many more) by routing the ad over the domain you're currently visiting."

https://greasyfork.org/en/scripts/418897-global-ad-remover-using-referrerpolicy

A new default Referrer-Policy for Chrome: strict-origin-when-cross-origin  |  Web  |  Google Developers
https://developers.google.com/web/updates/2020/07/referrer-policy-new-chrome-default