Here’s a head scratcher for the channel. My SCA store created sales order with two lines. Same item but one has a quantity of zero. Should that even be possible?

I'm 99% sure the Commerce API does not accept

addLine()

calls where the quantity is set to 0. However, a 0 quantity line in a NetSuite sales order is legitimate and I believe some customers have use cases. So my guess is that you have some sort of customisation that is responsible for creating lines in sales orders and it is using, for example, regular SuiteScript.

That gives me a few ideas on where to start the troubleshooting. Appreciated, @Steve Goldberg.

I've not checked it, but if the product listed is an item that cannot be fulfilled then it may accept the line. Is it definitely a product-based item? (And not some sort of service or other intangible item?)

It is a product-based item, yes.

I have the same issue some months ago, review if you have any customization using a custom column (line level), there must be cases where it is duplicating with zero and it is hard to identify since the issue is not consistently

Oh yes, this is another point I didn't mention: if a line is duplicated and it's for the same item, this may be because the duplicate line contains some sort of 'unique' column. Some customers don't want lines to combine in SuiteCommerce/NetSuite even if the item is exactly the same -- in those cases, randomly generated values can be injected into hidden custom columns, which makes them unique and therefore uncombinable.