Copy the documents from buy shipment to Order release when user is uploading 2 documents

Summary:

We need to copy the documents that are uploaded on Buy Shipment to respective Order Releases

So we have written an agent which triggers on "Shipment - upload document" event of type shipment and uses "Add Document to" action to copy the document from Buy Shipment to Order Release

So in a case where user while uploading the document selects 2 documents at the same time then this agent is not working

what additionally can be done for this case or do we need to configure something else

Content (please ensure you mask any confidential information):

We need to copy the documents that are uploaded on Buy Shipment to respective Order Releases