Try booting your iPhone 7 Plus into safe mode to see whether the problem is caused by other harmful apps. All third-party applications and services will be disabled as a result. As a result, isolating the problem and determining if a third-party app is at fault will be much easier. Remove any suspected malicious programs while in safe mode if required.

1. Hold the Power button down until the Slide to Power Off screen displays, then restart your iPhone. To totally turn off the gadget, slide it off. Then press and hold the Power button a second time.
2. Hold down the Volume Up button until the phone has fully restarted after you see the Apple logo.
3. You should be in safe mode at this time. You may then go to Cydia and uninstall any annoying apps.