https://beta.musicbrainz.org/report/ReleasesSameBarcode doesn't catch all duplicate barcodes because it does not ignore leading zeros.  For example, the Universal Music Group barcode prefix "602435" is not grouped together in the report and is separated based on how much padding was manually entered:

1. https://beta.musicbrainz.org/report/ReleasesSameBarcode?page=1
2. https://beta.musicbrainz.org/report/ReleasesSameBarcode?page=14
3. https://beta.musicbrainz.org/report/ReleasesSameBarcode?page=84

Barcodes that are stored as less than 14 digits in length should be left padded with zeros when the report is being processed so that padding doesn't cause effective duplicates to fall off the report.