网页代码写入.csv而不是查询结果。 错误

Why is this script writing the full PHP page code (css/html) to the .csv instead of my query results? I suspect it has something to do with the COM ADODB connection / "File reference for download.". I would change the connection type, but the COM connection seems to be required via colleague communications.

• Using PHP with COM ADODB Microsoft Access Driver

  $db = $_SERVER["DOCUMENT_ROOT"]."/CS_Sites.accdb";
  $conn = new COM("ADODB.Connection") or die("Cannot start ADO");
  $conn->open("Driver={Microsoft Access Driver (*.mdb, *.accdb)};Dbq=$db");
  
  $SRes_Q = $_POST["SiteResponsibilityQuery"];    
  
  $query = "SELECT [Site Name]";
  $query .= "FROM [Site Prioritization Factors]";
  $query .= "WHERE [Site Responsibility]= '$SRes_Q'";
  $rs = $conn->execute($query);
  
  //File reference for download.
  $filename = "CS_Site_Query_" . date('Ymd') . ".csv";
  header("Content-Disposition: attachment; filename=\"$filename\"");
  header("Content-Type: text/csv");
  $out = fopen('php://output', 'w');
  
  foreach($rs as $fields){
   fputcsv($out, $fields); 
  }
  fclose($out);