Update quantity on Item fulfillment with SOAP API

Hello,

We have issue when we ship partial quantity on item fulfillment.

If the quantity change on item fulfillement, we need to update as well inventoryassignement quantity. But if quantities are the last avaible for fulfillment :

• If we don't indicate inventorystatus we get an error that status is mandatory
• Please enter value(s) for: Status
• if we indicate the inventory status internalid, in our system it would be 1 (it is set as default), we get an error that the id is not valid.

<error>

<statusCode>INVALID_KEY_OR_REF</statusCode>

<message>Invalid inventorystatus reference key 1.</message>

<type>ERROR</type>

How to bypass this error ? In the meantime it is really annoying and time consuming, as part of our cancellation need to be done manually.