Using ZFS: Error: read ECONNRESET when trying to get my Groups

I'm attempting to execute the SEQ-pre-groups: Get my top-level groups, following the ZFS quick start.

1. I imported the Postman collection and it seems right
2. I've entered my API key/secret into the Environment and it seems right

Logs below (key and signature replaced with xxxxxxxxxx)

09:59:32.243 GET https://rms-world-check-one-api-pilot.thomsonreuters.com/v1/groups: {
  "Error": "read ECONNRESET",
  "Request Headers": {
    "date": "Thu, 19 Aug 2021 13:59:31 GMT",
    "authorization": "Signature keyId=\"xxxxxxxxxx\",algorithm=\"hmac-sha256\",headers=\"(request-target) host date\",signature=\"xxxxxxxxxx\"",
    "user-agent": "PostmanRuntime/7.28.3",
    "accept": "*/*",
    "postman-token": "60082bc7-ae26-4a32-a55e-4574d0bf3a73",
    "host": "rms-world-check-one-api-pilot.thomsonreuters.com",
    "accept-encoding": "gzip, deflate, br",
    "connection": "keep-alive"
  }
}