Beside show in group detail page, that banner show on another page? which page?
Your screenshot is not really clear for me, can you make it bigger, or separate the images (3 images), please? also provide me the steps to replicate it.
That ad - "iJoomla Test Ad" was an ad for test, and was created for this campaign - "iJoomla Test Campaign" and this campaign is not published, so this is the reason why you can't see this ad on front-end. You can delete this campaign and that ad, I kept this campaign and ad just to see that I was able to create ads from front-end.