MPGS Direct Payment 3DS cannot finalise payment

Question

I'm Trying to make the payment with 3DS work, I have followed the three steps in this link: https://eu-gateway.mastercard.com/api/documentation/integrationGuidelines/supportedFeatures/pickAdditionalFunctionality/authentication/3DS/integrationModelAPI.html?locale=en_US

My Process:

• Create a Session (Successful)

  POST to "https://cibpaynow.gateway.mastercard.com/api/rest/version/71/merchant/TEST123456/session/"

• Update the session with card details (Successful)

• Initiate Authentication (Successful)[example code in steps link] https://cibpaynow.gateway.mastercard.com/api/rest/version/71/merchant/TEST123456/order/1/transaction/2

• Authenticate Payer (Successful)[example code in steps link]

• Proceed to payment (X)[example code in steps link]

So the issue at the last step, which I don't understand why does it happen, is when I run this, as mentioned in the steps with providing order.id and authentication.trasanctionId:

{
    "authentication" :
    {
        "transactionId": "2"
    },
    "session": {
        "id": "SESSION0002873236543L1392791G59"
   },
    "order":{
        "amount":"1",
        "currency":"EGP",
        "reference" : "1"
    },
    "apiOperation": "PAY",
    "transaction":{
        "reference":"1"
    }
}

This is the response I get, which makes no sense since it should be the same transactionId that I was authenticating:

{
    "error": {
        "cause": "INVALID_REQUEST",
        "explanation": "A transaction with this transaction ID has already been processed but the request parameters do not match. To process a new transaction for this order, the transaction.id must be unique for the order."
    },
    "result": "ERROR"
}

Does anyone know what I did wrong?

========= EDIT ========

I May have concluded that it might be that I'm initiating a PAYER_WEBSITE authentication, and I'm PAYING through an api put request, I don't really know but this is my only explanation, if this is the issue how should I initiate an authentication that can be completed using a request that is not necessary to be from a website