Adrian Kingsley-Hughes for ZDNet:
I’ve received numerous complaints from iPhone owners who told me that iOS 13.1.2 is causing calls to drop within a minute or so of being placed. Social media, along with Apple’s own support forum, seems to suggest that this issue is quite widespread. I’ve also tested this and encountered the problem.
There’s no official fix, although some are claiming that carrying out a network reset — Settings > General > Reset > Reset Network Settings — may help. It did seem to help in my case.
Another issue that has raised its ugly and disruptive head is a battery drain issue, and there are even sporadic reports of overheating.
MacDailyNews Take: We expect iOS 13.2 will correct pressing issues like these.