Zoho Mail API Error EXTRA_KEY_FOUND_IN_JSON

I have a workflow set up in Pipedream that uses the Zoho Mail API to send emails from my account. It's worked without issue for months but today I'm getting the following 404 error for every email I try to send:

{ "data": { "errorCode": "EXTRA_KEY_FOUND_IN_JSON" }, "status": { "code": 404, "description": "Invalid Input" } }

I haven't made any changes to my code. Have the input requirements changed in the past few days? (The last time I ran the workflow was Thursday 12/9 and it ran fine.)

Here's the code I'm using to set up the request:

const {email_address, zoho_mail_account_id, access_token} = params.sender

const data = {
  fromAddress: email_address,
  toAddress: params.recipients,
  ccAddress: params.cc_recipients, 
  subject: params.subject,
  content: params.content,
  attachments: params.attachments.length ? params.attachments : null,
}

return await require("@pipedreamhq/platform").axios(this, {
  method: 'post',
  url: `https://mail.${auths.zoho_mail.base_api_uri}/api/accounts/${zoho_mail_account_id}/messages`,
  headers: {
    "Authorization": `Zoho-oauthtoken ${access_token}`,
  },
  data
})