I have an app in the Apple app store, that uses currently uses an Amazon banner ad. Works fine. I changed the code 2 weeks ago to refine how the banner is sized. In a separate project file for the same app, I am experimenting with interstitial ads. These files (the banner resize and interstitial tests) both worked perfectly, the ads loaded and showed correctly. I ran the test code multiple times in the xcode iOS simulator, trying different devices (iPhone and iPad models). Everything worked great. Last week, I ran the code again, and now, ads fail to load in these two projects, as well as the production code from which the current app store app was generated. What's going on? Why won't the ads load in the test code?