Our creatives are set to a high z-index default (999999-1000000). To avoid expansion layering issues, set any site-side drop down-menus (or float units) to a z-index higher than 1000001. This will ensure that drop-down menus expand properly over rich media.
For more information, see Site navigation drop-down menus are expanding under my rich media.
overflow:hiddento style ad container divs
To prevent expanding issues, use
For more information, see Expanding ad isn't expanding out of placement or over webpage.
In these scenarios, place the ad tag directly on the page and confirm the issue. If the issue persists, contact Google Marketing Platform support. If the issue is resolved, then it's a problem on the publisher's side.