After the phone automatically turns off the screen, it's unlocked without a password within 5s

Problem phenomenon: 

After the phone reaches the set system screen-off time and automatically turns off the screen, the screen is manually turned on within 5 seconds and you can enter the home screen without entering a password.

Solution: 

This function is to avoid the problem of needing to enter the password repeatedly in a short time. By default, you can re-enter the home screen within 5 seconds without repeated unlocking. If you are worried, you can manually press the power button to lock the screen.