Failed to connect with Amazon MQ Event Source from Lambda

Question

I have connected a RabbitMQ queue based of Amazon MQ to a Lambda such that whenever there is a message added to the queue, the lambda is triggered. Here is my SAM configuration:

MQConsumer:
    Type: AWS::Serverless::Function 
    Properties:
      CodeUri: tasks/
      Timeout: 900
      Handler: task.lambda_handler
      Runtime: python3.8
      FunctionName: some-func-name
      Policies:
        - Version: '2012-10-17'
          Statement:
            - Effect: Allow
              Resource: '*'
              Action:
              - mq:*
              - secretsmanager:GetSecretValue
              - ec2:CreateNetworkInterface
              - ec2:DescribeNetworkInterfaces
              - ec2:DescribeVpcs
              - ec2:DeleteNetworkInterface
              - ec2:DescribeSubnets
              - ec2:DescribeSecurityGroups
              - ses:SendRawEmail
      Events:
        MQEvent:
          Type: MQ
          Properties:
            Broker: !GetAtt MQBroker.Arn
            Queues:
              - tasks
            BatchSize: 1
            Enabled: true
            SourceAccessConfigurations:
              - Type: BASIC_AUTH
                URI: !FindInMap [EnvironmentVariables, SecretManagerArn, !Ref EnvironmentType]

Issues:

1. While the invocation happens whenever a message is added to the queue, I still see the following error displayed under Triggers in my lambda.

2. Every now and then, unpredictably the event source gets Disabled under the triggers and the workflow stops working. I would have to open console and manually re-enable it to process the unprocessed items in the queue.

How can I rectify this issue?