### 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_
test_port, invocations, proxy = start_http_server()
    yield test_port, invocations, proxy
    proxy.stop()
role_policy_su = {
    "Version": "2012-10-17",
    "Statement": [{"Effect": "Allow", "Action": ["*"], "Resource": ["*"]}],
}
@pytest.fixture(scope="session")
def lambda_su_role(aws_client):
    role_name = f"lambda-autogenerated-{short_uid()}"
    role = aws_client.iam.create_role(
        RoleName=role_name, AssumeRolePolicyDocument=role_assume_policy
    )["Role"]
    policy_name = f"lambda-autogenerated-{short_uid()}"
    policy_arn = aws_client.iam.create_policy(
        PolicyName=policy_name, PolicyDocument=json.dumps(role_policy_su)
    )["Policy"]["Arn"]
    aws_client.iam.attach_role_policy(RoleName=role_name, PolicyArn=policy_arn)
    if os.environ.get("TEST_TARGET", "") == "AWS_CLOUD":  
        time.sleep(10)
    yield role["Arn"]
    run_safe(aws_client.iam.detach_role_policy(RoleName=role_name, PolicyArn=policy_arn))
    run_safe(aws_client.iam.delete_role(RoleName=role_name))
    run_safe(aws_client.iam.delete_policy(PolicyArn=policy_arn))
@pytest.fixture
def create_iam_role_with_policy(iam_client):