Agree’d. I think you’ve proven that both your custom script and the default Asterisk start up script exhibit the same behaviour. i.e.: Both work when SELinux is disabled, or don’t work when it’s enabled. Thus, this isn’t an Asterisk problem but rather an SELinux configuration problem.
Either do as david551 suggests in other " [Errors dumping in /var/log/messages]" (Errors dumping in /var/log/messages) thread and disable SELinux, or figure out how to configure SELinux on your server.