Hidden Features of iOS 8…
iOS 10.0.3
iOS 10.0.3 fixes bugs including an issue where some users could temporarily lose cellular connectivity.
For information on the security content of this update, please visit this website: https://support.apple.com/kb/HT201222
Reasons :
A growing number of Verizon subscribers are complaining about a serious issue that causes them to regularly lose LTE connectivity on their iPhone 7 and iPhone 7 Plus devices, suggesting a major bug that needs to be resolved by either Apple or Verizon. «Mac Rumors»
Complaints about call connection problems with Apple Inc.’s iPhone 7 models are spreading across social media in China just weeks after the devices were released. «Bloomberg»