Hi.
I am using GP Premium.
I tried to add an adsense ad using Elements, but it did not work.
I found that an Adasense ad is shown when adding the same adsense code snippet TWICE via Element or when adding them to contnet-single.php.
I first suspected WPML for this issue and disabled it. But it did not resolve the problem.
Currently I added Adsense Code snippet twice via Element, showing one Adsense ad (and blank space for another ad) at the bottom of each post.