Cell F3 (ENG-2592). Initiator versus top frame (N13). A test-adblock.org frame on this test-adblock.com page requests its own site's /ad-scroll.js. Brave keys first party on the initiator (the frame), so it allows the request in Standard. Ours takes the top frame from the request's own Referer, which inside the frame is the frame's URL, so ours agrees without the extension (inventory correction 2). With the extension (Sec-Adblock-Ctx), ours sees the true top frame: third party, and the gate does not count TopLevelUrlSource.Extension as confident, so it blocks (D2, ENG-2392).
Rows, rules and Brave's verdicts are in pages/network-fixtures.json. The runner grades from CDP, never from this page.