Galaxy Note 8: How to reset the device?

If your device is frozen and unresponsive, you may need to close apps or turn off the device and turn it on again.

If your device is frozen and unresponsive, press and hold the Power key and the Volume down key simultaneously for more than 7 seconds to restart it.

If after restarting the device you still find your device freezes sometimes or is sometimes unresponsive, there are some actions you can try to help correct this symptom: 

If the problem is still not resolved, please contact Samsung Customer Care as per info under.