Chip's Samsung Galaxy mobile phone had a bunch of pictures on it, but they started disappearing. Leo says that there may be an app that is moving the photos to a folder, and they aren't really missing. Or the images are being uploaded and then deleted to preserve space. For instance, Google Photos does this. In fact, Leo recommends using Google Photos anyway, since Chip will be assured that his photos are being backed up to the cloud.
Leo advises wiping the phone, restoring it, and then taking some pictures. See if the images are still disappearing. If they are, then there's an issue with the OS. Leo suspects that it'll solve the problem.