nginx reload failed when using an encrypted key as ssl_certificate_key

for some reasons, we used an encrypted key as ssl_certificate_key.

After execute "./sbin/nginx -s reload", we expect ex worker process will be quit and new worker process will be create。
But unfortunately , EX worker process does not quit , new worker process does not be create.

attachments are certificates and private key for test , the password for key1.key is 123456. they were be created by openssl.

Thanks for your kind help!