Can't Join Apple Podcasts Connect - 409 Error from API

When I navigate to https://podcastsconnect.apple.com/landing and try to set up my Apple Podcasts account, I get an error after agreeing to the ToS and clicking "Save". I've checked the API responses using Chrome Dev Tools and this is what I get:

GET https://podcastsconnect.apple.com/WebObjects/iTunesConnect.woa/ra/v1/contentProviders
{
  "data": null,
  "messages": {
    "fieldMessages": {
      "$": [
        {
          "type": "error",
          "attributeName": "",
          "messageKey": "unableProcessRequest",
          "messageIndex": null,
          "isGeneric": true,
          "params": {}
        }
      ]
    },
    "error": null,
    "warn": null,
    "info": null
  },
  "statusCode": "409"
}

GET https://podcastsconnect.apple.com/olympus/v1/termsSignatures
{
  "errors" : [ {
    "id" : "97b9680b-27fe-4bfa-80aa-a3b5816ef36d",
    "status" : "409",
    "code" : "STATE_ERROR.TERMS_ALREADY_SIGNED",
    "title" : "This signature is invalid because this or a newer version of this terms type has already been signed.",
    "detail" : "You have already signed version 285391 of termsType PODCASTS_CONNECT"
  } ]
}

I can't contact Apple support either, since when I click on "Contact Us", it redirects me to the landing page because my account is not set up.