I think your system’s DNS might not be set up properly; DNS looks fine from my perspective:
$ host www.getseoranker.com
www.getseoranker.com is an alias for getseoranker.com.
getseoranker.com has address 34.90.19.171
$ host getseoranker.com
getseoranker.com has address 34.90.19.171
This isn’t a problem with Caddy, it’s a problem with your DNS config on whatever machine you ran that curl
command, I think.