Sandbox Checkout API - Payment Error 500

[RaimundoMonzon]

I have come back into a project that i havent touched in a while, and noticed the payments were not working as they used to. I have't checked if something changed and my request is out of date, however i don't think that's it. I'm performing payments as usual and keep getting the 500 Internal server error, I have tried to input a bad request on purpose and it does return the "Bad Request error message". The following is my Terminals output.
`PS C:\Users\Acari\Desktop\portfolio-web> npm run start

[email protected] start
node api/index

Servidor en marcha en el puerto: 3000
Conexion con la Base de Datos establecida.
{
items: [
{
_id: '672c3618334d168d11ac67e3',
title: 'Starry Night',
price: 18750,
quantity: 1
}
],
totalPrice: 18750,
_id: '6796d201660a1a6be84fa66e',
expireAt: '2025-01-27T00:23:29.923Z'
}
CARD_TOKEN: 1ae28956e326b1af4c0cb193b7f7f660
PAYMENT INFO: {
body: {
application_fee: null,
binary_mode: false,
campaign_id: null,
capture: false,
coupon_amount: null,
description: 'Payment for product',
differential_pricing_id: null,
external_reference: 'MP0001',
installments: 1,
metadata: null,
payer: {
entity_type: 'individual',
type: 'customer',
email: '[email protected]',
identification: [Object]
},
payment_method_id: undefined,
token: '1ae28956e326b1af4c0cb193b7f7f660',
transaction_amount: 18750
},
requestOptions: { idempotencyKey: 'f4649100-1efb-47a9-bfbb-2dba1eaba6e1' }
}
PAYMENT ERROR: { message: 'internal_error', error: null, status: 500, cause: [] }`

And this is the code i'm using:
`import { MercadoPagoConfig, Payment } from "mercadopago";
import { MP_ACCESS_TOKEN } from "../helpers/config.js";
import { v4 as uuidv4 } from 'uuid';

export class PaymentService {

constructor() {
    this.client = new MercadoPagoConfig({
        accessToken: MP_ACCESS_TOKEN,
        options: {
            environment: 'sandbox', // Cambiar a 'production' para producción.
            timeout: 5000,
            idempotencyKey: uuidv4()
        }
    });

    this.payment = new Payment(this.client);
}

async createPayment(items, totalPrice, reqBody) {

    const token = await this.generateCardToken(reqBody.cardInfo);
    console.log("CARD_TOKEN: ", token);

    const paymentInfo = {
        body: {
            
            application_fee: null,
            binary_mode: false, // En false la transaccion puede devolver PENDIENTE.
            campaign_id: null,
            capture: false,
            coupon_amount: null,
            description: 'Payment for product',
            differential_pricing_id: null,
            external_reference: 'MP0001',
            installments: 1, // Número de cuotas.
            metadata: null,
            payer: {
                entity_type: 'individual',
                type: 'customer',
                email: reqBody.email, // E-mail del comprador.
                identification: {
                    type: reqBody.cardInfo.cardholder.identification.type, // DNI, Pasaporte, etc.
                    number: reqBody.cardInfo.cardholder.identification.number // Numero de identificación.
                }
            },
            payment_method_id: reqBody.payment_method_id, // ID del método de pago. Por ejemplo, master o visa.
            token: token, // Token de la tarjeta, generado a partir de la tarjeta.
            transaction_amount: parseInt(totalPrice) // El total de la compra.
        },

        requestOptions: { idempotencyKey: uuidv4() } // Generar UUID para cada petición.
    };

    console.log("PAYMENT INFO: ", paymentInfo);
    return await this.payment.create(paymentInfo)
        .then(result => console.log("PAYMENT RESULT: ", result))
        .catch(error => console.error("PAYMENT ERROR: ", error));
}

async generateCardToken(card) {
    const response = await fetch('https://api.mercadopago.com/v1/card_tokens', {
        method: 'POST',
        headers: {
            Authorization: `Bearer ${MP_ACCESS_TOKEN}`,
            "Content-Type": "application/json",
        },
        body: JSON.stringify(card),
    });

    const data = await response.json();
    return data.id;
}

}`

If anyone has any idea as to what could be causing this trouble please let me know, I've noticed this is quite a recurrent matter, so if it's a temporal issue from the API also let me know about it.