We're at that point again in the iOS lifecycle, the point where Apple is busy playing whack-a-mole with bugs only to accidentally bake more bugs into the code. This seems to be what's happening with iOS 13's latest release -- iOS 13.1.2 -- which introduced a new and frustrating bug that takes the phone out of iPhone.
Must read: iOS 13: Security and privacy settings you need to tweak and check
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. Here are some tips and tricks to help you diagnose and fix battery issues.
If you have updated to iOS 13.1.2, hang in there for Apple to release an update -- although it seems that the call bug currently also exists in the iOS 13.2 beta, which isn't comforting. If you're not yet updated, I suggest giving this one a miss.