Google Pub Sub unacknowledged Messages taking more than a minute to consume again

In Google pub sub, unacknowledged messages takes more than a minute to consume. In the console I have configured the ackDeadline to 10 second. So it suppose to reconsume after 10 second but it is taking around 1 min 3 second.

public class StudentUpdateEventConsumer1 {

@Autowired
private PubSubTemplate pubSubTemplate;

@Autowired
private ApplicationConfig applicationConfig;

@Bean
public MessageChannel studentUpdateEventInputChannel() {
    return new PublishSubscribeChannel();
}

@Bean
public PubSubInboundChannelAdapter studentUpdateEventMessageChannelAdapter(
        @Qualifier("studentUpdateEventInputChannel") MessageChannel inputChannel,
        PubSubTemplate pubSubTemplate) {
    PubSubInboundChannelAdapter adapter =
            new PubSubInboundChannelAdapter(pubSubTemplate, "pub-sub-test-topic-sub-1");
    adapter.setOutputChannel(inputChannel);
    adapter.setAckMode(AckMode.MANUAL);
    adapter.setPayloadType(Student.class);
    return adapter;
}

@ServiceActivator(inputChannel = "studentUpdateEventInputChannel")
public void messageReceiver(
        Student payload,
        @Header(GcpPubSubHeaders.ORIGINAL_MESSAGE) BasicAcknowledgeablePubsubMessage message) throws InterruptedException {
    log.info("Message arrived via an inbound channel adapter from pub-sub-test-topic-sub-1! Payload: {}", payload);
    // message.ack();
}

}