Kit Item "quantityavailable" returns NaN value?

Trying to get the Quantity Available value for a Kit Item when order is place via the website. Currently I get a NaN value, where the script works if order is created via the back end.

My question is... why can you get the Quantity Available value for Kit Items when the order is created via the backend but not when the order is created via the store? Is there a workaround I should be using?

function processWebOrders(){
try {
  if (type == 'create') {
 
   var newId = nlapiGetRecordId();
   var newType = nlapiGetRecordType();
  
   var soRec = nlapiLoadRecord(newType, newId);
  
   var orderNum = soRec.getFieldValue('tranid'); // get Sales Order #