yeah, I think it's how it handles the ad blockers. Some ad blockers checks after the page is rendered, and if the height of the page (ad?) is expected, then they don't kick in. But ad blockers that don't render the ad are then broken because they don't render the page as per the blocker detector. So Brave downloads and renders the whole then and then goes back to remove the ads. I guess during the removal, they don't do a great job at it.