The benefits of the Auto-logout parameters are correct in the documentation:

https://www.zabbix.com/documentation/6.0/en/manual/web_interface/user_profile

Problem: The "Auto Logout" option is offset by the "Remember me for 30 days" option on the login screen. If whether the "Remember me for 30 days" button is clicked and the "Auto Logout" option change to 0 after the next login. 

Suggestions for improvement:

1.Implement the dependence of the "Remember me for 30 days" option on the "Auto-logout" option

OR

2. Exclude the influence of the "Remember me for 30 days" option on the "Auto-logout" option and vice versa.