Adsense responsive ad doesn't show image?

Hey!

I recently updated my website to be fully responsive and with that I also changed to the responsive adsense ad formats. The problem is that the new formats don't display images at all, even if there is more than enough space for them, which resulted in much less revenue.

Does someone know what is the reason and how to fix it?

EDIT: To clarify, the ad is being show as text only but no banner ads (images) are shown.