Reboot, Update, Backup, Recovery; Reboot Or Force Reboot - OnePlus 9RT 5G User Manual

You can go to Settings > Apps management > Display over other apps
to view and configure supported apps. When you open the specified
application in Display over other apps, the app will create a picture-in-
picture window when you open or leave the application (such as
continue to watch video), which displays on top of the other apps you
are currently using.
* This function needs to be supported by the application itself.

Reboot, Update, Backup, Recovery

Learn to upgrade and reset your OnePlus device

Reboot or force reboot

Most issues can be resolved by rebooting your device in the following
two ways:
1. When powered on, press power button and volume up button
simultaneously, and then tap "Restart" to reboot the device.
2. When powered on, long press the power button and volume up
button for 10 seconds, the phone will shut down, and then press the
power button to turn on the device again.
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