Disabling the GNOME automatic screen locking
In the interest of safety and privacy, the GNOME automatic screen lock is enabled by default.
When the screen locks after a period of inactivity, you must enter your password to unlock the screen.
You can disable this feature at any time.
To disable the GNOME automatic screen lock, complete the following steps.
On the desktop, navigate to the upper-right corner of the screen and click the arrow icon to expand the desktop options. Click the Settings icon.
From the the Settings menu, select Privacy.
On the Privacy page, select Screen Lock, and toggle the switch from On to Off.
Close the window and verify that in the Privacy page, the Screen Lock is Off.
To enable the automatic screen lock, repeat this process and toggle the switch from Off to On.