Starting from 2.0 zabbix frontend login form has a "Remember me for 30 days" checkbox and it's enabled by default.

What I observed:
if user profile option "Auto-login" is *un*checked and if the "Remeber .." checkbox in login form is checked - zabbix frontend performs these SQLs:

BEGIN
SELECT   u.userid,u.alias,u.autologin,u.autologout FROM users u WHERE u.userid='1'
UPDATE users SET  autologin='1', userid='1', autologout='0' WHERE userid='1'
COMMIT

when an "Auto-login" in user profile is checked and the "Remeber .." is *un*checked on login form, then these SQLs:

BEGIN
SELECT   u.userid,u.alias,u.autologin,u.autologout FROM users u WHERE u.userid='1'
UPDATE users SET  autologin='0', userid='1' WHERE userid='1'
COMMIT

Note: these SQLs are not visible in frontend at all, they can be caught only by general mysql logging.

As the result "Auto-logout (min 90 seconds)" parameter value is lost !
I have to admit that it's enough unexpected.
It's not reflected in documentation at all !

Using/unusing the "Remeber .." checkbox during login an user loses its own value for "Auto-logout (min 90 seconds)" parameter in profile.
Losing any configuration value - it's very bad, IMO.

Actually the "Auto-login" option just enables an expiration date for a "zbx_sessionid" cookie, so it's preserved for 30 days when browser may be restarted.

What to do - will de described in comments, to discuss.