dompdf without css applied

Problem/Motivation

Hello everyone,

I have an installation on Drupal 7 and dompdf latest release (2.0.3); php engine is 8.1.x.

dompdf is correctly loaded, but the rendered pdf does not have the custom css loaded. There are no errors in watchdog and I can't find a solution. I also set some options, without solving:

$dompdf->set_option('isHtml5ParserEnabled', TRUE);
$dompdf->set_option('isRemoteEnabled', TRUE);
$dompdf->set_option('chroot', DRUPAL_ROOT);

Thank you very much for any help you can provide.