Recently some users spoke on Twitter, saying that after the new iphone was upgraded to iOS 12.1.2, there was unable to connect operator and failed to use mobile data. According to user distribution, iPhone users in North America, South America, Europe, and Asia are currently affected by signals and are most severe in the United States.
From the feedback of users, the problem is mainly concentrated on the cellular network, and WiFi is not affected. When the user turns on the cellular network, even if the cellular network connection is successful, when the browser or other application is opened, the user cannot access the Internet.
After the problem broke out, many industry people have offered advice and suggestions, saying that in the above problems, you can turn off the WiFi call function and LTE HD call function in the settings. However, from the results, it can only temporarily solve the problem of data network connection, and can not be completely solved.
But If the user have updated their iphone to new system iOS 12.1.2, if there is a problem and there is no retreat, they could only wait for Apple to update the system