Make sure your iPhone is up to date.
Tap Settings > General > Software Update
Latest iOS version available for a 6S Plus is 11.2.6.
Make sure your iPhone is up to date.
Tap Settings > General > Software Update
Latest iOS version available for a 6S Plus is 11.2.6.
It could be a hardware issue. I suggest that you make an appointment with the Apple Genius Bar.
It started with the last update.
iPhone 6sPlus