PHP - 下载脚本仅下载300B而不是170MB

I'm having an issue when trying to make a download script on my website. What ends up happening is that it only downloads between 160B to 310B instead of the whole 170MB that the file is. I'm not sure why it's happening, and if anyone can help that would be greatly appreciated. Also, I'm not sure if it's an issue with the code itself or that my host doesn't allow big files to be downloaded, as I get this message on net2ftp: "Files which are too big can't be downloaded, uploaded, copied, moved, searched, zipped, unzipped, viewed or edited; they can only be renamed, chmodded or deleted."

Here is my code:

ignore_user_abort(true);
set_time_limit(0);

$path = "/versions/";
$dl_file = $_GET['file'];
$fullPath = $path.$dl_file;

if ($fd = fopen($fullPath, "r")) {
  $fsize = filesize($fullPath);
  $path_parts = pathinfo($fullPath);

  header("Content-type: application/octet-stream");
  header("Content-Disposition: filename=\"".$path_parts["basename"]."\"");
  header("Content-length: $fsize");
  header("Cache-control: private");
  while(!feof($fd)) {
    $buffer = fread($fd, 2048);
    echo $buffer;
  }
}
fclose($fd);
exit;