It appears that the phones, responding to user complaints that their battery life was pants, had started shutting down and restarting while the device is charging through MagSafe or Lightning.

The first post  eight days ago said:

I just got the iPhone 14 Pro and ever since I noticed that it restarts while charging (magsafe/cable). I cant find anything online and other than that it functions as normal. It does not restart at all while its off the charger?

Another user moaned their iPhone 14 Pro Max, on iOS 16.0.1, was restarting every 10-20 minutes while charging. Some other people reported that even on iOS 16.0.2 or iOS 16.1 beta, the problem persists.

Apple Support helpfully gave the following advice which apparently works about as well as a chocolate teapot so we would not bother.

Full restore from backup with DFU;
Full restore from backup with Recovery Mode;
Disable optimised charging;
Uninstall Eufy app;
The user then said:

The best option, for those who can, would be to return their iPhone within the 14-day period and then buy another one perhaps something for about half the price and with a better operating system.