A very unpleasant problem, but Apple already knows about it.
IPhone and iPad users are actively complaining that after installing iOS 12.1.2 on their devices became irregular with a connection to the cell network. Some of the users reported that the problem is not solved by either restarting or even resetting the network settings on the device. Apple responds to all the messages about the issue through his microblogging support Twitter, but those fixes bug yet.
12.1.2 iOS — iPhone does not catch the network
According to user reports, on their iPhone or iPad stopped to catch the network right away after installing iOS 12.1.2. As soon as the patch was successfully installed, mobile devices, hung unpleasant words “No service”. Eliminate it and return to full health on their own could only those users who have rolled back to the previous iOS version 12.1.1.
It is noteworthy that in iOS 12.1.2 Apple has fixed this problem for iPhone users in Turkey. However, as shown by the feedback of users, the problem manifests itself on the iPhone and in other countries. With a surge of feedback on the problem started just after the release of iOS 12.1.2.
It should be noted that the number of users who are faced with a problem, can not be called huge. However, a problem with iOS 12.1.2 there and Apple will fix it in iOS 12.1.3, which is under testing. However, it is possible that iOS 12.1.3 will be released in 2019.