If your iPhone isn’t working right, try restarting it.
Turn iPhone off and on
To turn iPhone off, do one of following:
iPhone X and later: Simultaneously press and hold the side button and either volume button until the sliders appear, then drag the top slider.
Other models: Press and hold the side button or Sleep/Wake button (depending on your model), then drag the slider.
All models: Go to Settings > General > Shut Down, then drag the slider.
To turn iPhone back on, press and hold the side button or Sleep/Wake button (depending on your model) until the Apple logo appears.
If you can’t turn iPhone off and on, try forcing it to restart.