$.post stopped working after DNS/SSL change (edited)

Question

We inherited a PHP script that posts to an endpoint using curl. The original developers are out of touch, and the client isn't clear on what it does - just that they want to keep it the way it is.

The script worked fabulously, until recently when we updated the site's domain name. The only other change I can think of that might've affected it is adding an SSL certificate, I don't think we re-tested the email function after that point, which means it could've been broken since then.

Copy and pasting the script below. If you like to take a look and let me know what you think is going wrong, that would be really helpful :) (The company domain name has been removed and replaced with "XXXX" to honor their privacy.)

Edit: I believe the php script below might not even be running - adding the js that calls it below. The issue may be with the $.post method....

sendmail.blade.php

@php

 
   $fullName = $_POST["fullName"];
   $user_number = $_POST["user_number"];
   $email = $_POST["email"];
   $daytimePhoneNumber = $_POST["daytimePhoneNumber"];

   $m = $_POST["message"];
$xml = <<<EOD
<?xml version="1.0" encoding="UTF-8"?>
<ContactUs>
 <Source>Corporate Site</Source>
 <Name>$fullName</Name>
 <MemberNumber>$user_number</MemberNumber>
 <eMail>$email</eMail>
 <Phone>$daytimePhoneNumber</Phone>
 <Comments>$m</Comments>
</ContactUs>
EOD;

  $fields = array("xml"=>$xml);
  $url = "https://prod-rest.XXXX.org/ContactService.svc/PostContact";

  $ch = curl_init($url);
  curl_setopt($ch, CURLOPT_HEADER, 0); // set to 0 to eliminate header info from response
  curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1); // Returns response data instead of TRUE(1)
  curl_setopt($ch, CURLOPT_POST, 1);
  curl_setopt($ch, CURLOPT_POSTFIELDS, $xml); // use HTTP POST to send form data
  curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-Type: text/xml'));
  curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE); // uncomment this line if you get no gateway response. ###
  curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
  curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);
  $resp = curl_exec($ch); //execute post and get results
  curl_close ($ch);
  $handle = fopen($_SERVER["DOCUMENT_ROOT"]."/xmlanswer.html", 'w');
  fwrite($handle, $resp);
  fclose($handle);

  if(strpos($resp,"<ERRORDESCRIPTION>Success</ERRORDESCRIPTION>")!==false) {
   echo "ok";
  } else if(strpos($resp,"<ERRORDESCRIPTION>")!==false) {
     $pos1 = strpos($resp,"<ERRORDESCRIPTION>")+18;
     $pos2 = strpos($resp,"</ERRORDESCRIPTION>",$pos1);
     echo substr($resp,$pos1,$pos2-$pos1);
  } else {
     echo $resp;
  }   exit;


@endphp

post_submit_contact.js

$(function(){
  var submittedFlag = false;
  $('#contact-form').submit(function() {
    var msg,
    form = $(this);

    // check that url exists
    $.get("/wp-content/themes/quorum-theme/sendmail.blade.php").done(function () {
      console.log("url ok");
    }).fail(function () {
       console.log("url failed");
    });

    if (!submittedFlag) {            
      submittedFlag = true;
      document.form1.submit.disabled = true;
      $.post('/wp-content/themes/quorum-theme/sendmail.blade.php', form.serialize(),
        function (data) {                    
          msg = "_____________________________________\n\n";
          msg += "Your request has been submitted\n";
          msg += "Our administration business hours are\n";
          msg += "Monday-Friday (excluding holidays)\n";
          msg += "8:30 a.m. 7:00 p.m. ET.\n";
          msg += "_____________________________________\n\n\n";                    
          alert(msg);                    
          form[0].reset();
          $('.input-container').removeClass('no-error');                    
          $('#myCounter').html(600);                    
        });
      return false;
    } else {
      alert("You have already submitted this form; please wait for the submission to complete.");
      return false;
    }
  });
});