Hello. I currently have an iPhone 6s running iOS 9.3.4. I gave my son my old iPhone 6 which runs iOS 10.2.1. I currently run the 2 devices and 4 others off of the same apple ID. For some reason, I am able to view all of my son's incoming/outgoing call logs on my personal device. Is there any way to prevent this? I have contacted my carrier about this and they cannot resolve my problem. Any help would be appreciated. Thanks.