If you encounter issues with missing zeroes in your Excel file when you have barcodes to upload, do refer to our workaround below:
Open TextEdit on (MacOS) or Notepad (Windows).
Open the CSV file in TextEdit/Notepad.
Press CTRL + A to select all, CTRL + C to copy the raw text to Google Sheets.
Open Google Sheets. Paste the data at Column A1.
Go to Format > Number > Change the entire sheet to Plain Text.
Highlight the 1st column (Column A), go to Data > Split Text to Column. After that, all leading zeroes will appear in the barcode column.
Finally, apply a Filter or Pivot Table to find out which barcode has the leading zero.