Missing Ads on New Posts

Hey. Absolute love this plugin, but whenever I publish a post it takes a couple of minutes (maybe 5 or 10) before the ads start to show. Until then, the spaces in my posts where the ads should show are white boxes.

Also, I’ve noticed after a while, posts that are months old have had their ads removed and only show when you flush the cache on the post page.

Would really like ads showing instantly on new posts… Any help?