View this info if your Note9 is frozen or unresponsive.
This device has a non-removable battery. This process can be used to simulate a 'battery pull' when the device is frozen or unresponsive..
In most cases, a soft reset won't affect data on the device, unless the battery is very low.
Press and hold the Power and Volume Down buttons until the device powers off (approx. 10 seconds).
Allow several seconds for the Maintenance Boot Mode screen to appear.
From the Maintenance Boot Mode screen, select Normal Boot.
Utilize the volume buttons to cycle through the available options and the lower left button (on the left edge; below the volume buttons) to select.
Allow up to 90 seconds for the reset to complete.