DescribeContact is returning undefined AgentInfo

I am using DescribeContact to retrieve the assigned agent id as suggested here, however AgentInfo is returning "undefined" despite there being an agent assigned. I've tried placing the lambda in both agent and customer whisper flows, and with using auto accept or manual accept, and the result is the same. Am I doing something wrong, or is this method not real time?

My code (simplified):

import { ConnectClient, DescribeContactCommand } from '@aws-sdk/client-connect';
export const handler = async(event) => {
    const client = new ConnectClient();
    
    var input = {
      ContactId: event['Details']['ContactData']['ContactId'], /* required */
      InstanceId: "XXXXX" /* required */
    };

    const command = new DescribeContactCommand(input);
    const response = await client.send(command);

    return response.Contact;
};

The returned response having undefined AgentInfo:

Contact: {
    AgentInfo: undefined,
    Arn: 'arn:aws:connect:us-east-1:657086911202:instance/XXXX/contact/9b57ea60-f114-4970-a7ed-557998bde650',
    Channel: 'VOICE',
    Description: undefined,
    DisconnectTimestamp: undefined,
    Id: '9b57ea60-f114-4970-a7ed-557998bde650',
    InitialContactId: undefined,
    InitiationMethod: 'INBOUND',
    InitiationTimestamp: 2023-06-22T13:52:14.336Z,
    LastUpdateTimestamp: 2023-06-22T13:53:52.008Z,
    Name: undefined,
    PreviousContactId: undefined,
    QueueInfo: {
      EnqueueTimestamp: 2023-06-22T13:53:36.994Z,
      Id: 'bd705363-373a-4483-bd94-b33297febf46'
    },
    ScheduledTimestamp: undefined
  }