Call log history shared on two iphones

Hi everyone. Me and my mom share the same apple id on our iphones. We both got the 12 models. The two iPhones share the same calls history. I have tried every possible way the anyone ever suggested to stop this thing but it won’t stop. I have tried to to turn off handoff and iCloud drive amd icloud contacts options. Calling on other devices is turned off also. Nothing works. I don’t want to sign out of the apple id because the two iPhones have a lot of things downloaded via that apple id. And signing in a new apple id on an iPhone that has too many data and apps on it is not something any iPhone user would do. Unless you have any tips on how to transfer every thing related to one apple id to another one without losing any data or apps.