[Koha] Label Creator Module Question

Hello everyone, as someone new to Koha (version 3.16.04) I've been struggling with the Label Creator Module in printing out barcodes and other fields. After creating a layout and template the barcode will be printed in a PDF, however no other fields (title, author) are present. In their place will be a "0". I've tried listing both the MARC field as well as the database column names when using a layout. The exported CSV file for the same batch correctly shows the indicated fields for each item, but I'm not sure why the PDF export isn't showing them as well. Has anyone encountered something like this while using the label creator module, or perhaps knows that I'm doing wrong? Thank you for any advice you can offer. - Evan