Sure, but why do the two different versions of curl give different results? With 7.64.1:

  % curl --dump-header /dev/tty 'http://1.1/'
  HTTP/1.1 403 Forbidden
  Date: Sun, 11 Sep 2022 19:01:53 GMT
  Content-Type: text/plain; charset=UTF-8
  Content-Length: 16
  Connection: close
  X-Frame-Options: SAMEORIGIN
  Referrer-Policy: same-origin
  Cache-Control: private, max-age=0, no-store, no-cache, must-revalidate, post-check=0, pre-check=0
  Expires: Thu, 01 Jan 1970 00:00:01 GMT
  Server: cloudflare
  CF-RAY: 7492a7924b2bd895-CPH

  error code: 1003

(Note that curl 'https://1.0.0.1/' works just fine, so it's not like curl is blocked by the server on general principle.)

With 7.85.0:

  % curl --dump-header /dev/tty 'http://1.1/'
  HTTP/1.1 301 Moved Permanently
  Server: cloudflare
  Date: Sun, 11 Sep 2022 19:03:09 GMT
  Content-Type: text/html
  Content-Length: 167
  Connection: keep-alive
  Location: https://1.0.0.1/
  CF-RAY: 7492a96a181df18a-PIT

  <html>
  <head><title>301 Moved Permanently</title></head>
  <body>
  <center><h1>301 Moved Permanently</h1></center>
  <hr><center>cloudflare</center>
  </body>
  </html>