Confirmation Request is failing in SAP Integration Suite, managed gateway for spend management and SAP Business Network with the below error message:

"Bad Request" and Error Code:"400" and Error Code Response:"Error:Previous confirmation can not be found. Please contact support with the Error Reference Number: ANERR-50000000000000002082848007 for more details. Suggested Action : Document Failed in SAP Business Network.For further assistance, please contact SAP Support with the code mentioned in Response.Managed Gateway for Spend&Network Support Error Code : CIG-PLT-00644

The cXML structure sent by supplier is wrong.

How the cXML structure is being sent (Incorrect):

<ConfirmationHeader confirmID="XXXXXX" noticeDate="2020-05-04T08:53:30+02:00" operation="update" type="allDetail"/>
<OrderReference orderID="XXXXXXX">
<DocumentReference payloadID="payload of the Purchase Order"/>
</OrderReference>

How the cXML structure should be sent (Correct):

<ConfirmationHeader confirmID = "XXXXXXXX" operation = "update" type = "detail" noticeDate = "2020-05-04T08:53:30+02:00" version = "1">
<DocumentReference payloadID="payloadID of previous order confirmation"/>
</ConfirmationHeader>
<OrderReference orderID = "XXXXXXXX">
<DocumentReference payloadID = "payload of Purchase Order"/>
</OrderReference>

Supplier is not referring the previous Order Confirmation (OC) payload ID correctly or it is missing in the current OC cXML.

SAP Integration Suite Managed Gateway > Managed Gateway for Business Network