500 status trying ciBuildRuns

Hello all!

Since past Thursday, using this cURL:

curl  -X POST \
  'https://api.appstoreconnect.apple.com/v1/ciBuildRuns' \
  --header 'Accept: */*' \
  --header 'User-Agent: Thunder Client (https://www.thunderclient.com)' \
  --header 'Authorization: Bearer XXXX' \
  --header 'Content-Type: application/json' \
  --data-raw '{
  "data": {
    "type": "ciBuildRuns",
    "attributes": {},
    "relationships": {
      "workflow": {
        "data": {
          "type": "ciWorkflows",
          "id": "NNNN"
        }
      },
      "sourceBranchOrTag": {
        "data": {
          "type": "scmGitReferences",
          "id": "NNNN"
        }
      }
    }
  }
}

Of course, I removed the sensible information from my sample. This is the response:

{
  "errors": [
    {
      "status": "500",
      "code": "UNEXPECTED_ERROR",
      "title": "An unexpected error occurred.",
      "detail": "An unexpected error occurred on the server side. If this issue continues, contact us at https://developer.apple.com/contact/."
    }
  ]
}

I have written to Apple Support twice since they assure me that I will have a response in 2 working days, but I have not had any response.

The rest of the API calls work correctly.