Chip has a Samsung Galaxy S5 & S3 and his images are disappearing, in lieu of so called "no media" files. Leo says that usually indicates that the internal storage is failing. Leo says he's not supposed to see the no media files at all. So if they're appearing, there's definitely an issue. He could try clearing the phone's cache. He should also make sure he accepts the updates. Leo's also suspecting that there's an app on the phones that is causing bad behavior. Bringing the OS up to date can often fix issues like this.