Duplicate phantom DPD shipment created after one successful WZA create command

Hello,

We are experiencing a recurring DPD-specific issue when creating shipments through the Wysyłam z Allegro API.

For each affected order, our application sends exactly one request to:

POST /shipment-management/shipments/create-commands

The command completes successfully and creates one valid WZA shipment with:

- carrierId: DPD_HU
- a valid label
- one valid waybill
- one WZA shipment ID and one create command ID

However, several minutes later, Allegro automatically adds a second shipment to the same order with:

- carrierId: DPD
- a different, usually consecutive waybill
- no WZA shipment ID
- no create command ID
- no downloadable label
- no possibility to delete it through the Allegro interface or public API

Our findings:

- Only one WZA create command was sent per order.
- The deprecated deliveryMethodId field was not included when its value was null.
- In the latest case, three DPD shipments were created in one batch. All three phantom shipments appeared at exactly the same second, approximately eight minutes later.
- The issue occurs only with DPD.
- We have not observed it with EXPRESS_ONE.
- According to the seller, DPD shipments created directly in the Allegro interface do not produce these duplicates.
- The issue has affected approximately 40 orders.

The complete list of checkoutForm IDs, valid waybills, erroneous waybills, WZA shipment IDs and command IDs has already been submitted privately to Allegro Support. We can provide the support ticket number and technical identifiers privately.

Could you please escalate this to the Wysyłam z Allegro / DPD technical team and investigate which backend process creates the second DPD shipment?

Thank you.