Enabling the Apache ProxyPreserveHost directive

The ProxyPreserveHost directive is used to instruct Apache mod_proxy, when acting as a reverse proxy, to preserve and retain the original Host: header from the client browser when constructing the proxied request to send to the target server.

The default setting for this configuration directive is Off, indicating to not preserve the Host: header and instead generate a Host: header based on the target server's hostname.

If this is not what is wanted, you should add the ProxyPreserveHost On directive to the Apache HTTPD configuration, either in httpd.conf or related/equivalent configuration files.