We not suppose to turn on the PHP default config.
Apparently, I have the same issue when I ran the test on sslabs.com.
Another issue is : This server supports weak Diffie-Hellman (DH) key exchange parameters.
Solution:
Note: This process may takes 15 to 30 mins depends on your service specs.
1. Go to and run:
2. Add this line at the beginning of the vhost config:
ssl_dhparam /etc/ssl/certs/dhparam.pem;