Codeigniter会话在不同的URL中不起作用

Question

After some values in session codeigniter is not saving given value in session. For example, in 1st page I have 2 session variables:

Array
(
    [session_id] => 655dasdasfdce7cfe9dd6asd9faead406
    [ip_address] => ip_address
    [user_agent] => Mozilla/5.0 (Windows NT 6.3; WOW64; rv:44.0) Gecko/2010301 Firefox/44.0
    [last_activity] => 14696222
    [user_data] => 
    [csrf] => Array
        (
            [token] => xyz
        )

    [logged_in] => Array
        (
            [id] => 1
            [cus_email] => [e-mail]
            [company_id] => 1
        )
    [third_value] => Array
        (
            [example] => 1
        )
)

When I add third session variable. It's showing me on first page. But, not in second.

Is it memory issue or time_out?

memory_limit is 128M in php.ini

config.php

$config['sess_cookie_name'] = 'ci_session';
$config['sess_expiration']  = 7200;
$config['sess_expire_on_close'] = TRUE;
$config['sess_encrypt_cookie']  = FALSE;
$config['sess_use_database']    = FALSE;
$config['sess_table_name']      = 'ci_sessions';
$config['sess_match_ip']    = FALSE;
$config['sess_match_useragent'] = TRUE;
$config['sess_time_to_update']  = 300;