Turns out its caused by a uBlockOrigin EasyList entry which thinks we are an ad since we call ourselves "popout.html". See this entry: e7883cfe74/easylist/easylist_general_block_popup.txt (L42) Fixes https://github.com/microsoft/playwright/issues/23799
e7883cfe74/easylist/easylist_general_block_popup.txt (L42)