Some users report that the iPhone does not show incoming calls. Others are unhappy that the earpiece and microphone stop working during calls.
Sometimes the iPhone itself interrupts the call.
@AppleSupport Ever since the latest IOS 13.1.2 I have been experiencing dropped calls on virtually every call made, the conversation all of a sudden sounds like it’s buffering and then it cuts. Pls help
– Corne Swanepoel (@ corne2) October 10, 2019
Since the release of the latest version of iOS 13.1.2, I am faced with the fact that almost every call made is interrupted, the conversation suddenly starts to sound like buffering and then breaks off. Please help.
Some of the bugs can be fixed by resetting the network. This is done through Settings → General → Reset → Reset network settings.
Another problem with iOS 13.1.2 is the increased power consumption, which sometimes leads to a strong heating of the device. Users note that some iPhones began to work on iOS 13.1.2 much less than on the latest versions of iOS 12.
Apple will probably continue to fix bugs and optimize battery performance in future versions of iOS. But while users have to put up with all the shortcomings of iOS 13. [ZDNet]