Why are the tracking numbers wrong in Shopify?
We see this issue when orders are partially created in Addition then reviewed/edited within the Australia Post portal.
When you use the the AusPost portal (either MyPost or eParcel/Parcel Send) for part of the fulfilment process, then and go into review your shipments, AusPost recreates the tracking number but never sends that back to Addition/Shopify - hence the erroneous tracking numbers.
If you've made edits/reviewed a shipment in the AusPost portal, you will need to copy the new tracking number from AusPost and update the Shopify order.
To avoid this going forward we suggest managing the fulfilment process completely within the Addition app.