Make sure you're contacting hhs.gov and not www.hhs.gov, the www. subdomain reacts differently.
$ printf 'GET / HTTP/1.1\r\nHost: hhs.gov\r\n\r\n' | nc hhs.gov 80
HTTP/1.1 302 Found
Date: Mon, 14 Oct 2024 01:38:29 GMT
Server: Apache
Location: http://www.hhs.gov/web/508//
Content-Length: 212
Content-Type: text/html; charset=iso-8859-1
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>302 Found</title>
</head><body>
<h1>Found</h1>
<p>The document has moved <a href="http://www.hhs.gov/web/508//">here</a>.</p>
</body></html>
^C
$ printf 'GET / HTTP/1.1\nHost: hhs.gov\n\n' | nc hhs.gov 80
HTTP/1.1 400 Bad Request
Date: Mon, 14 Oct 2024 01:38:40 GMT
Server: Apache
Content-Length: 226
Connection: close
Content-Type: text/html; charset=iso-8859-1
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>400 Bad Request</title>
</head><body>
<h1>Bad Request</h1>
<p>Your browser sent a request that this server could not understand.<br />
</p>
</body></html>
This exercise was about demonstrating that our security can't rely on making sure there's a carriage return in HTTP line termination, because there is no such norm. See the root of the thread, where I asked the question.
Oh, I agree it's about that too, but my point is you've already volunteered more time and resources investigating the situation than most companies would be willing to spend.