Barcodes and multiple shots

We are testing out barcode scanners and have an issue with subsequent shots. If we go into "next camera naming" and scan the code, then select underscore and one digit counter, it does not name the next capture as xxxxxxx_2 and so forth, it comes in as xxxxxxx_38 and up. Is there a preference I need to reset, or a work around? Interested to see who else is shooting tethered with barcode scanners. Thanks!