I'm sorry about the issue. Please try the following fix:
- On both iPhones, Settings app icon, then tap on option FaceTime (scroll down as needed), then turn OFF the option iPhone Cellular Calls.
- On both iPhones, open Settings app icon, then open the option Phone (scroll down as needed), then turn OFF the option All Calls on Other Devices.
- If that still does not work, if you and your wife use the same Apple ID account (using the same email address for Apple ID account), then create a new Apple ID account at the website below:
, then do the following on one iPhone only:
- Open Settings app icon, then open option iTunes & App Stores (scroll down as needed)
, then tap on the current Apple ID / email address
, then tap on Sign out
, then sign in with the new Apple ID account you've just created.
Please reply at the box below to continue troubleshooting. Thank you.
Yes, when upgrading software, it might reset some settings. You can set each phone to use a different Apple ID (email address). But usually if software update turns on the option iPhone Cellular Calls, then you just turn that off, then it should resolve the issue.
Please let me know. Thank you.