Hi mex,

It was installed via the RHEL 7 repo.

I've managed to solve the issue, and so for anyone else experiencing this odd behavour the solution is to check the SELINUX file context.

My config was in a file that had "unconfined_u:object_r:var_t:s0" and it needed "unconfined_u:object_r:httpd_config_t:s0" so run "sudo restorecon -v /path/to/conf"

Otherwise nginx just silently ignores the file, and no error shows up in the audit.log file. (or disable SELINUX, but alas I can't)

Regards,
Daniel Sage