Cannot Remove Line Item - not working at all (nlapiRemoveLineItem)

I am trying to "simply" remove an item from a Sales Order sublist on an item fieldchange. The script is firing on the correct item as I have inserted test alerts informing of this.

I have read the endless posts on the topic and nothing has worked.

Could someone please help me out here?

What I have tried...

1.
var listId = 'item' //sales order sublist
var totalItems = nlapiGetLineItemCount(listId);
    for(i = 1;i <= totalItems ;i++)
    {
        nlapiSelectLineItem(listId, 1);
        nlapiRemoveLineItem(listId, 1);
        nlapiCommitLineItem(listId);
    }
   
    //cancel uncommited items
    nlapiCancelLineItem('item');

2. Simple attempt to remove first item...
        nlapiSelectLineItem('item', 1);
        nlapiRemoveLineItem('item', 1);
        nlapiCommitLineItem('item');

3. Even simpler attempt....