You could try a normal Reset by holding the home button and the sleep / wake button at the same time until the white Apple Logo appears, then stop holding the buttons and wait until your iPhone comes back up on your lock-screen. After the Reset, go to Settings>General>Reset and depress "Reset All". After that you will need to put some passwords back in to WiFi and other Apps and look through your Apps for manually resetting your preferences for that Apps Notifications and Location Services settings. This procedure has eliminated the screen sensitivity issue for some iPhone 6 / 6 Plus owners. If that doesn't work then you will need to ensure a good iTunes Backup and current iTunes version and Restore the iPhone to Factory Settings. When the iTunes prompt asks if you want to Restore from Backup or Setup as New choose Setup as New. When the iPhone has completed the Restore and you have tested the Screen Sensitivity you can re-connect to iTunes and Restore from your current Backup.





It is possible on the other hand that you actually have a Hardware Problem in which case you will need to either make a Genius Bar Appointment at a nearby Apple Store or you will need to call AppleCare Support on a landline and they may have you run basic Diagnostics via Quick Test. They may send you a box to return the iPhone for another New iPhone 6 Plus.