nats-server: jetstream could not pull message after nats-server restart

i was testing jetstream on nats-server v2.3.2. one sender and one receiver program are running for quite a long time.

this is what my stream look like :

	_, err = js.AddStream(&nats.StreamConfig{
		Name:      streamName,
		Subjects:  []string{streamSubjects},
		Storage:   nats.FileStorage,
		Replicas:  3,
		Retention: nats.WorkQueuePolicy,
		Discard:   nats.DiscardNew,
		MaxMsgs:   -1,
		MaxAge:    time.Hour * 24 * 365,
	})

this is how i create the consumer:

	if _, err := js.AddConsumer(streamName, &nats.ConsumerConfig{
		Durable:       durableName,
		DeliverPolicy: nats.DeliverAllPolicy,
		AckPolicy:     nats.AckExplicitPolicy,
		ReplayPolicy:  nats.ReplayInstantPolicy,
		FilterSubject: subjectName,
		AckWait:       time.Second * 30,
		MaxDeliver:    -1,
		MaxAckPending: 1000,
	}); err != nil && !strings.Contains(err.Error(), "already in use") {
		log.Println("AddConsumer fail")
		return
	}

this is what the subscriber look like:

	sub, err := js.PullSubscribe("ORDERS.created", durableName, nats.Bind("ORDERS", durableName))
	if err != nil {
		fmt.Println(" PullSubscribe:", err)
		return
	}
       msgs, err := sub.Fetch(1000, nats.MaxWait(10*time.Second))

when i restart my nats-server cluster nodes(upgrade to nats-server 2.3.3), the consumer can no longer pull messages even if i restart my consumer program. the Fetch call just return : “nats: timeout”, but i’m sure there are lots of message in the working queue. only if i delete the consumer by calling js.DeleteConsumer(streamName, durableName), recreate it, my program can resume fetching messages. actually, every time i restart nats-server nodes, my consumer program encouter the same problem.

there is another issue, after i restart nats-server nodes, restart my program, it sometimes reports : “PullSubscribe: nats: JetStream system temporarily unavailable”

I expect nats-server nodes restarting action not impacting jetstream clients fetching messages.