here is the code I am using to create the line: soid.insertLine({ sublistId: 'item', line: x+1 }); soid.setSublistValue({ sublistId: 'item', fieldId: 'item', line: x+1, value: 27035 });

I would not recommend using

soid

as the name of the variable that is the record object. It's confusing for someone else down the line. Change to

rec

or

soRec

, something like that.

'off by 1' may be a good motivator for using NFT where the code looks more like

so.item[x].item = 27035

or maybe even

const newline = so.item.addLine(); newline.item = 27035

what is NFT?