TI-API: Order-API not working "K9 Failed" error message

Hello E2E-Forum,

we can't order over the Order-API, neither production or test environment. Everytime the Order-API is sending a "K9 failed" error message.

The request content to the order-api (tried prod/test):

{
  "order": {
    "checkoutProfileId": "xxx",
    "customerPurchaseOrderNumber": "test",
    "expediteShipping": false,
    "endCustomerCompanyName": "TEST-xxx",
    "lineItems": [
      {
        "tiPartNumber": "TPS79318DBVR",
        "customReelIndicator": false,
        "quantity": 100
      },
      {
        "tiPartNumber": "TPS65910A3A1RSLR",
        "customReelIndicator": false,
        "quantity": 10
      }
    ]
  }
}

The response message:

{{"errorCode":"ERR-TICOM-ORDER-API-0009","type":"K9","message":"K9 Failed"}}

Already checked Appruve, new api key generated and tried validating the checkoutprofile. Everytime the same error message.

Best regards