When httpd was started by apachectl start command, LLAWP didn't start completely.
Besides that, the below error was output in Apache error_log.
[Error] SiteMinder Agent
Unable to load SiteMinder host configuration object or host configuration file.
/{home_web_agent}/config/SmHost.conf
SELinux caused this issue as the below message was output in error_log:
[notice] SELinux policy enabled; httpd running as context unconfined_u:system_r:httpd_t:s0
Change SELinux status from "enforcing" to "disabled" (1) to solve this issue.