Thank you for providing the details. I was able to load ads with all your Ad Unit IDs using our
sample apps on an Android device. From my understanding, since your apps are enrolled for "
Designed For Families" program, they constitute a smaller portion of the regular ads stack. This may limit the ads returned from the ad inventory. As we handle only technical SDK related queries, you will have to reach out to the
AdMob Product Support Team to get this resolved.