Latest issue to hit Apple; phone app freezes on iPhone 7, iPhone 6s and iPhone 5s
Additionally, some Apple iPhone 6s units manufactured between September and October 2015 are shutting down with the battery going from 30% to 0% in the blink of an eye. You can check on Apple's support website to see if you are entitled to a free battery replacement.
The latest problem with the iPhone has been discussed on the Apple Support Communities forum. There, owners of the Apple iPhone 7, iPhone 6s and even the Apple iPhone 5s are complaining that their phone application is freezing. This is preventing them from making and taking phone calls, or handling other phone related operations. It appears that for many, this problem started after the update to iOS 10.1.1. For some, the problem came with the update to iOS 10. Soft and Factory resets are not helping.
Apple has yet to acknowledge this issue, but the company initially did the same with Touch Disease and the so-called #BatteryGate problems. It is hoped that iOS 10.2 will fix this issue. Right now, iOS 10.2 Beta 5 has been disseminated to developers and members of the public beta program, which means that iOS 10.2 is close at hand.
source: AppleSupportCommunities via Forbes