In Netsuite I have two different accounts. In one if i go to a sales order, fulfill it and save that the sales order status turns from Pending Fulfillment to Fulfilled and the "fulfillingtransaction" field in the sales order links to the new IF record. In the other acct when i fulfill the sales order the status stays in Pending Fulfillment and the "fulfillingtransactoin" does not get populated. In both systems if I go to the History-Related Records tab on the order, the link to the IF exists. Any idea of why the one does not link an fulfillingtransaction and change its status but the other does? I am assuming there is some accounting setting for that.
Check the default initial item fulfillment status. It sounds like in the first account you have it setting immediately to Shipped, whereas in the second account you have it setting to Picked or Packed. Complete the pick, pack and ship process to have it update the status.