Subscribing a Profile doesn't add it to the list

Hello everyone!

I am encountering a weird issue trying to subscribe an email through the API. I have a custom form created on a NextJS application, and whenever a user adds their email, i post the email to https://a.klaviyo.com/api/profile-subscription-bulk-create-jobs/ with all the required options (code further down.) I get back a 202 response with the status “Accepted”, but, the email cannot be found in a list, or anywhere for that matter.

The list has the “Double opt in” disabled.

Im saying its weird because a week ago everything worked without any issue and no change to the code happened since. And also the response seems ok. 

Here is the code i am using: 

async function subscribe(request, response) {
  const { email, listId } = JSON.parse(request.body);
  const options = {
    method: "POST",
    headers: {
      accept: "application/json",
      revision: "2023-02-22",
      "content-type": "application/json",
      Authorization: `Klaviyo-API-Key ${APIKey}`,
    },
    body: JSON.stringify({
      data: {
        type: "profile-subscription-bulk-create-job",
        attributes: {
          list_id: listId,
          custom_source: "Marketing Website",
          subscriptions: [
            {
              channels: { email: ["MARKETING"] },
              email,
            },
          ],
        },
      },
    }),
  };

  try {
    const res = await fetch(
      "https://a.klaviyo.com/api/profile-subscription-bulk-create-jobs/",
      options
    );
    response.json({
      response: res,
    });
  } catch (error) {
    response.json({
      error
    });
  }
}

Ive triple checked the list id exists and is sent correctly, triple checked the API key is correct. 

Ive tried creating a brand new list and still doesn't work. 

Ive ran out of options so any ideas would be helpful. 

Thank you!