QZDASOINIT file update question.

I'm hoping someone can help me find the culprit...

We have a process in place (for a number of years) where an order is
created in dotNet and then copied to the IBMi for processing by the
warehouse.

At a more detailed level an external sp is called to create an empty Order
header on the IBMi with the status set to 'T' (temporary) and the order
number is returned.
As each line is added to the order in dotNet an external sp is called
passing the order number, item and quantity to add to the order on the IBMi.
When all the lines have been added in dotNet they press a button to submit
the order and at that time a QZDASOINIT job sets the status of the order to
blank on the IBMi signifying the order may be processed by the warehouse.

The order header is journaled and I see all these actions in the journal.
As expected I see the external programs from the sp calls in jopgm for the
order creation and the addition of the order lines. But the last step
where the status of the order is set to blank the jopgm is QZDASOINIT.

I've scanned all our sources using PDM, RDi, X-Analysis. I've also checked
for triggers on the order header, searched sysroutine and checked for the
order status field in the routine_definition and I can't find anything.

I'm pretty sure as the JOPGM in the journal is QZDASOINIT that the setting
of the order status to blank is not done by a program on the IBMi but how
do I prove or confirm this?

Sorry for the lengthy post and thanks in advance for any insight,

Rob