### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

When starting the transcription job in response job object is null:

<img width="1154" alt="Screenshot 2023-04-03 at 09 21 09" src="https://user-images.githubusercontent.com/454412/229447066-1671f811-da49-478d-bf24-252f30b17699.png">


### Expected Behavior

Response from the real AWS stack - job object is not null

<img width="1161" alt="Screenshot 2023-04-03 at 09 30 13" src="https://user-images.githubusercontent.com/454412/229441498-06125248-3b68-4679-8204-0163e8245db6.png">


### How are you starting LocalStack?

Custom (please describe below)

### Steps To Reproduce

Using test containers, reproducing project can be found here:

https://github.com/kkocel/local-stack-transcribe-repro

### Environment

```markdown
- OS: macOS
- LocalStack: latest
```


### Anything else?

_No response_
usernames = []
    def _create_user(**kwargs):
        if "UserName" not in kwargs:
            kwargs["UserName"] = f"user-{short_uid()}"
        response = iam_client.create_user(**kwargs)
        usernames.append(response["User"]["UserName"])
        return response
    yield _create_user
    for username in usernames:
        inline_policies = iam_client.list_user_policies(UserName=username)["PolicyNames"]
        for inline_policy in inline_policies:
            try:
                iam_client.delete_user_policy(UserName=username, PolicyName=inline_policy)
            except Exception:
                LOG.debug(
                    "Could not delete user policy '%s' from '%s' during cleanup",
                    inline_policy,
                    username,
                )
        attached_policies = iam_client.list_attached_user_policies(UserName=username)[
            "AttachedPolicies"