Actual Delivery date is populating with a default date when a shipment is updated through API

Hi,

I am trying to update DFFs in Shipment using below webservice:

/fscmRestApi/resources/11.13.18.05/shipmentTransactionRequests

Payload :

{

"ActionCode": "ShipmentUpdate",

"shipments": [  {  

      "Shipment": "58009",   

     "shipmentDFF": [{
"freightChargeLineNumber": "3",    

        "ccProcessingFeeLineNumber": "4"}]    }]
}

Actual_delivery_date column is getting populated with a default value when i try to update shipment DFFs.

Is there any solution so that only dffs can be updated and not this actual_delivery_column.

Thanks.