If your mailing's ads are appearing in the wrong place even after you've checked/edited the settings, you could be facing an issue where your RSS feed's ads are interfering with your mailing's ad settings.
If you have ads turned on for your FeedBlitz RSS feed, the ads from the feed will override your newsletter ad settings.
To rectify this issue, switch the source URL for your newsletter from your FeedBlitz URL to your source URL.
Your source URL is located in the quick info tile of your RSS dashboard.
If you still see the wrong ads when viewing the newsletter preview after you've made this change, clear your browser cache and refresh the page.
If you want an extra ad in your newsletter, you will need to insert the ad directly into the template editor using an affiliate ID number.