QuickBooks POS添加SalesOrder提示Customer not found问题求助

I'm stuck on a frustrating issue while using the QuickBooks Web Connector to create a SalesOrder with QBPOSXML. Let me walk through what's going on:

The QBPOSXML Request I'm Executing #

<?xml version="1.0" encoding="UTF-8" standalone="yes"?> 
<?qbposxml version="3.0"?> 
<QBPOSXML> 
  <QBPOSXMLMsgsRq onError="stopOnError"> 
    <SalesOrderAddRq requestID="253182747"> 
      <SalesOrderAdd> 
        <CustomerListID>400001000663</CustomerListID> 
        <SalesOrderType>SalesOrder</SalesOrderType> 
        <SalesOrderItemAdd> 
          <ListID>288</ListID> 
          <Qty>2</Qty> 
        </SalesOrderItemAdd> 
      </SalesOrderAdd> 
    </SalesOrderAddRq> 
  </QBPOSXMLMsgsRq> 
</QBPOSXML>

The Persistent Error Response #

<QBPOSXML> 
  <QBPOSXMLMsgsRs> 
    <SalesOrderAddRs requestID="253182747" statusCode="20006" statusMessage="Customer 400001000663 not found" statusSeverity="Error"> 
      <SalesOrderRet/> 
    </SalesOrderAddRs> 
  </QBPOSXMLMsgsRs> 
</QBPOSXML>

Steps I've Already Taken to Debug #

• I've verified repeatedly that the customer with ListID 400001000663 exists in my QuickBooks POS customer list (see screenshot below):
  
• I've cross-checked the QBPOS SDK documentation, which clearly states that CustomerListID is the unique QBPOS ID used to identify a referenced customer.
• I've gone through official SDK examples but still can't figure out why the system is rejecting a valid customer ID.

Has anyone encountered this exact problem before? Or can anyone spot a detail I might be overlooking here?

内容的提问来源于stack exchange，提问作者B. Abdo