Eclipse Milo OPCUA StacklessClosedChannelException

Question

I'm using eclipse milo to connect to an opcua server I get StacklessClosedChannelException. Trying with a client like OPCUA Explorer I can connect correctly and read the variables. Below is my code:

    int codMacchina = macchina.getCodMacchina();
        String ipServer = macchina.getIpServer();
        String porta = macchina.getPorta();
        String username = macchina.getUsername();
        String password = macchina.getPassword();
        
        try {
            List<EndpointDescription> endpoints = 
            DiscoveryClient.getEndpoints("opc.tcp://" + ipServer + ":" + porta).get();
            EndpointDescription configPoint = endpoints.get(0);
           
            OpcUaClientConfigBuilder cfg = new OpcUaClientConfigBuilder();
            cfg.setEndpoint(configPoint);
            cfg.setIdentityProvider(new UsernameProvider(username, password));

            OpcUaClient client = OpcUaClient.create(cfg.build());
            CompletableFuture<UaClient> cf = client.connect();
            cf.get();

        .....

do you have any idea what i'm doing wrong?

INCLUDE STACK TRACE:

[2023-06-13][15:16:28:847][ERROR][AbstractLoggingWriter][71][java.util.concurrent.ExecutionException: io.netty.channel.StacklessClosedChannelException ] [2023-06-13][15:16:28:885][ERROR][AbstractLoggingWriter][71][ at java.base/java.util.concurrent.CompletableFuture.reportGet(CompletableFuture.java:395) ] [2023-06-13][15:16:28:899][ERROR][AbstractLoggingWriter][71][ at java.base/java.util.concurrent.CompletableFuture.get(CompletableFuture.java:1999) ] [2023-06-13][15:16:28:913][ERROR][AbstractLoggingWriter][71][ at deployment.GnuttiHubEar.ear.GnuttiHub.war//it.gnuttihub.job.ImportaDatiOPCUAJob.lambda$0(ImportaDatiOPCUAJob.java:70) ] [2023-06-13][15:16:28:932][ERROR][AbstractLoggingWriter][71][ at java.base/java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1654) ] [2023-06-13][15:16:28:947][ERROR][AbstractLoggingWriter][71][ at java.base/java.util.stream.ReferencePipeline$Head.forEach(ReferencePipeline.java:658) ] [2023-06-13][15:16:28:961][ERROR][AbstractLoggingWriter][71][ at deployment.GnuttiHubEar.ear.GnuttiHub.war//it.gnuttihub.job.ImportaDatiOPCUAJob.executeJob(ImportaDatiOPCUAJob.java:53) ] [2023-06-13][15:16:28:974][ERROR][AbstractLoggingWriter][71][ at deployment.GnuttiHubEar.ear.GnuttiHub.war//it.gnuttihub.job.AbstractJob.execute(AbstractJob.java:24) ] [2023-06-13][15:16:28:988][ERROR][AbstractLoggingWriter][71][ at deployment.GnuttiHubEar.ear.GnuttiHub.war//org.quartz.core.JobRunShell.run(JobRunShell.java:202) ] [2023-06-13][15:16:29:001][ERROR][AbstractLoggingWriter][71][ at deployment.GnuttiHubEar.ear.GnuttiHub.war//org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:573) ] [2023-06-13][15:16:29:018][ERROR][AbstractLoggingWriter][71][Caused by: io.netty.channel.StacklessClosedChannelException ] [2023-06-13][15:16:29:031][ERROR][AbstractLoggingWriter][71][ at io.netty.channel.AbstractChannel$AbstractUnsafe.ensureOpen(ChannelPromise)(Unknown Source)