Stripe - nosuch setupintent

I was following the stripe docs to create a Subscription.

BOTH LIVE AND SECRET KEYS ARE SET CORRECTLY, at least i Think

On my server when user registers:

import Stripe from 'stripe';
const stripe = new Stripe('sk_test_xxx...',
    {
        apiVersion: '2020-08-27'
    }
);

export const createUser = async (
    req: Request,
    res: Response,
    _next: NextFunction
) => {
// User logic
const customer = await stripe.customers.create({
    email: req.body.email
});
user.stripeCustomerId = customer.id;

await user.save();

const subscription = await stripe.subscriptions.create({
    customer: customer.id,
    items: [
        {
            price: price_id
        }
    ],
payment_behavior: 'default_incomplete',
expand: [ 'latest_invoice.payment_intent' ]
});

// Sending the payment_intent, ... back to the frontend
responseToSend = {
    user: user,
    payment: {
        subscriptionId: subscription.id,
        clientSecret:
            subscription!.latest_invoice.payment_intent.client_secret
        }
    };
}

On the frontend (React):

const stripePromise = loadStripe(
'pk_test_xxx...'
);

...
<Elements stripe={stripePromise} options={options}>
    <RegFormStripe />
</Elements>

Which shows payment element: Code in RegFormStripe:

import React, { useState, useEffect } from 'react';
import {
    PaymentElement,
    useStripe,
    useElements
} from '@stripe/react-stripe-js';

const RegFormStripe = () => {
    const stripe = useStripe();
    const elements = useElements();

    const [ errorMessage, setErrorMessage ] = useState(null);

    const handleSubmit = async (event) => {
        // We don't want to let default form submission happen here,
        // which would refresh the page.
        event.preventDefault();

        if (!stripe || !elements) {
            // Stripe.js has not yet loaded.
            // Make sure to disable form submission until Stripe.js has loaded.
            return;
        }

        const { error } = await stripe.confirmSetup({
            //`Elements` instance that was used to create the Payment Element
            elements,
            confirmParams: {
                return_url: 'http://localhost/payment-status'
            }
        });

        console.log(error);

        if (error) {
            // This point will only be reached if there is an immediate error when
            // confirming the payment. Show error to your customer (e.g., payment
            // details incomplete)
            setErrorMessage(error.message);
        } else {
            // Your customer will be redirected to your `return_url`. For some payment
            // methods like iDEAL, your customer will be redirected to an intermediate
            // site first to authorize the payment, then redirected to the `return_url`.
        }
    };

    return (
        <form onSubmit={handleSubmit}>
            <PaymentElement />
            <button disabled={!stripe}>Submit</button>
            {/* Show error message to your customers */}
            {errorMessage && <div>{errorMessage}</div>}
        </form>
    );
};

export default RegFormStripe;

Entering card details results in: No such setupintent: 'pi_xxxx' I googled for similar errors, they all said that the problem was in the API keys. So i tried generating new ones, replacing them, triple checked that they are correct. They might be initialized wrongly, but the content of API keys should definitely be correct.