GraphQL Transform AppSync service error: not supported through the realtime channel

Describe the bug I am trying out this tutorial here: https://dev.to/playra/aws-datastore-283f

I’m trying to get subscriptions working through AWS AppSync Console on the queries tab, but the service is returning a bunch of errors.

• schema uses model and auth directive,
• backend provisioned for DataStore
• no libraries used, tests done through AWS AppSync Console

Amplify CLI Version 4.18.0

To Reproduce Steps to reproduce the behavior or terminal output if applicable

1. amplify init, amplify add auth, choose email
2. amplify add api, Use this schema,

type Job
  @model
  @auth(
    rules: [
      {allow: owner, ownerField: "owner", operations: [create, update, delete]},
    ])
{
  id: ID!
  position: String!
  rate: String!
  description: String!
  owner: String
}

1. amplify update api, choose enable for DataStore
2. amplify push
3. amplify console auth, user pools, create a user with verified email, note the sub of the user, grab the app client id from the other tab as well,
4. amplify console api, Queries tab, login using the app client id, email, and password, will prompt to update password, then make sure you are logged in.
5. Create a new Job

mutation createJob($input: CreateJobInput!) {
  createJob(input: $input) {
    id
    position
    rate
   description
    owner
    _version
    _deleted
    _lastChangedAt
  }
}
{
  "input": {
    "id": "111",
    "position": "1",
    "rate": "100",
    "description": "desc",
    "owner": "eb8f6fc5-78b7-41a1-b1fa-9bc6dd61bdb7" // replace this with your sub 
  }
}

1. Job is created successfully. Open another console to create a subscription on the data

subscription onCreateJob($owner: String!){
  onCreateJob(owner: $owner) {
    id
    position
    rate
    description
    owner
    _version
    _deleted
    _lastChangedAt
  }
}
{
  "owner": "eb8f6fc5-78b7-41a1-b1fa-9bc6dd61bdb7"
}

1. Fails with

Error: {
    "errors": [
        {
            "message": "Connection failed: {\"errors\":[{\"errorType\":\"UnsupportedOperation\",\"message\":\" not supported through the realtime channel\"}]}"
        }
    ]
}
    at Object.error (https://d2i3s4ccv6vp01.cloudfront.net/c838cd42dec424b3e3864f2d31611d91308b8975/main.js:135:834636)
    at d (https://d2i3s4ccv6vp01.cloudfront.net/c838cd42dec424b3e3864f2d31611d91308b8975/main.js:174:1290919)
    at m (https://d2i3s4ccv6vp01.cloudfront.net/c838cd42dec424b3e3864f2d31611d91308b8975/main.js:174:1291263)
    at e.value (https://d2i3s4ccv6vp01.cloudfront.net/c838cd42dec424b3e3864f2d31611d91308b8975/main.js:174:1292345)
    at n._handleIncomingSubscriptionMessage (https://d2i3s4ccv6vp01.cloudfront.net/c838cd42dec424b3e3864f2d31611d91308b8975/main.js:135:664618)

Expected behavior Subscriptions work as expected.

Additional context So interestingly this was working earlier: I was able to create a subscription connection, go back to other tab and create a Job mutation. my subscription got a bad response because because i missed putting description in the selection set of the createMutation and subscription had selection set with description was expecting non-null description to come back… So i wonder if that caused the AppSync service to be in a weird state and now I can’t get the subscriptions to connect anymore.

When i miss adding the required selection set in the createJob mutation, the subsription received this error:

{
  "data": {
    "onCreateJob": null
  },
  "errors": [
    {
      "message": "Cannot return null for non-nullable type: 'String' within parent 'Job' (/onCreateJob/description)",
      "path": [
        "onCreateJob",
        "description"
      ]
    }
  ]
}

[lawmicha]

When using the AWS AppSync console to create subscriptions, make sure your document only has that single operation. I had two since i wanted to test the onCreateJob and onUpdateJob. Removing the second operation in my document worked

[blau2]

This is still an issue. When trying to establish a subscription through the AppSync console, it fails when there is more than a single operation present. It works fine as long as the subscription is the only operation.