Tax rate with 0%

[amdev]

Hi,

we have got customers with Shopify Online orders coming in with one particular line item marked as taxable but the tax line is showing GST with 0% and $0 tax amount. The rest of the line items are non-taxable and no `tax_lines` has been attached to them. We would like to know what would be the cause of such a line item to be marked as taxable rather than non-taxable. Thank you.