iPhone 5s iOS 9.2.1 Problems
The iOS 9.2.1 update is causing problems for some iPhone 5s users.
We continue to see complaints about iOS 9.2.1 issues. These problems include issues with Wi-Fi, Bluetooth, battery life, apps, Apple Music, problems with contacts, installation issues, and more. We expect complaints to continue well into iOS 9.2.1's life.
These problems appear to be isolated. We haven't heard about any widespread iOS 9.2.1 bugs other than the iPhone 6s battery percentage issue. Still, you'll want to be careful.
Dig into potential problems and again, make sure you prepare for this update. A little prep work will go a long way toward preventing problems on your iPhone.