This is a mismatch between the SW and the spec. As per spec, writing and parsing of pps_scaling_list_ref_layer_id syntax element should only happen when pps_infer_scaling_list_flag is equal to 1.

The condition should be added to the encoder and the decoder:

 if (pcPPS->getPpsInferScalingListFlag())
 {
   WRITE_CODE(pcPPS->getPpsScalingListRefLayerId(), 6, "pps_scaling_list_ref_layer_id");
 }

  if (pcPPS->getPpsInferScalingListFlag())
  {
    READ_CODE( 6, uiCode, "pps_scaling_list_ref_layer_id" ); pcPPS->setPpsScalingListRefLayerId( uiCode );
  }