Most of the times a server hosts multiple sites. So for example the server 127.0.0.1 can host example.org and example.com. Both sites can have different content. So when talking to 127.0.0.1 - how can the server decide what content deliver? Maybe this is your problem. (I don't know for not knowing the configuration of the server.)
So probably you have to find a way to talk to the given IP while sending the right name.
For more background information I recommend https://www.rfc-editor.org/rfc/rfc2068 (or any newer RFC).