You can't get out if you press the SMS function key.

It may be caused by too many programs running in the background, so some programs running in the background are shut down and restarted; It may be caused by the lack of memory in the mobile phone. I suggest you use the mobile phone housekeeper to clean up the memory of your mobile phone. For the virtual key: occasionally the virtual key doesn't work, it is recommended to press the on-off key or touch the screen with your hand to eliminate static electricity; For mobile phone keys: if individual keys fail, restart the mobile phone and observe again; If the power button fails, or all buttons fail and cannot be restarted, it is recommended to try to hold down the power button+volume up button 15S at the same time. If it still cannot be used, it is recommended to back up the important information of the mobile phone and restore the mobile phone to the factory setting operation; The above operation methods still can't be used after trying. It is recommended to take the purchase invoice and warranty card to the nearest after-sales outlet (customer service center) for professional testing.