I would like to inspect the rendered HTML elements in the iframes, at sites like codepen, codesandbox. However, the iframe context selector button doesn't show up. Its also greyed out in the dev tools settings, and as visible in the image, I have the required option enabled. This feature works as intended, in the default versions of Firefox. Tried Firefox Beta version 89.0b9. I am on Windows 10, using Firefox Developer Edition version 89.0b9.