Only from admin settings is not enough for session timeout.
You must also update the settings in php.ini
Lets set the session for one year !!!
From Magento admin, got to:
Stores > Configuration > Advanced > Admin > Security
Set the value of
Admin Session Lifetime (seconds) to
Now open you
php.ini file and change following two values:
In order to ensure that you are editing the correct
php.ini, create a
info.php file with the following content:
And hit that file to see all the php settings.
You can see the php.ini file path and the above settings as well.