重复的字符在Dompdf中显示为“？”

I'm trying of creating a relatively simple PDF

$pdf = new \Dompdf\Dompdf();
$pdf->loadHtml("0000003");
$pdf->render();
$pdf->stream("Test.pdf");

The output is coming as 0????03 instead of 0000003 (see below)

What might I be doing wrong?