Pull subscription is not handling messages

[githubmafio]

Hello. I have the following problem.

I used this code to subsribe

                jsc.PullSubscribeAsync(
                    _config.Subject,
                    (_, args) => ProcessMessage(args.Message, _handler),
                    ConsumerConfiguration.Builder()
                        .WithDurable(durableName)
                        .WithFilterSubject(_config.Subject!)
                        .WithAckPolicy(AckPolicy.Explicit) // non editable
                        .WithAckWait(_config.AckWaitMs)
                        .WithMaxPullWaiting(1000)
                        .WithDeliverPolicy(DeliverPolicy.All) // non editable
                        .WithInactiveThreshold(Duration.OfHours(_config.InactiveThresholdWindowHours))
                        .WithMaxDeliver(_config.MaxDeliver)
                        .WithReplayPolicy(ReplayPolicy.Instant)
                        .BuildPullSubscribeOptions());

In this case ProcessMessage is not called! But i use PullSubscribeAsync it is working.