After upgrading from 2360 our Windows slaves connecting via WebSockets have an instable connection (I did not try it for Linux slaves).
Windows slave are using Java 11.0.15.1

After some "Read side closed" information (while no job is running) a "Failed to synchronize IO streams ..." is noticed while a job is running.
Such a connection break causes a failed job.

The slave connects via 

curl -sO https://my-jenkins-master/jenkins/jnlpJars/agent.jar
java -jar agent.jar -jnlpUrl https://my-jenkins-master/jenkins/computer/myslave/jenkins-agent.jnlp -secret ############# -workDir "c:\Jenkins"

The log on the slave contains the following:

Aug. 30, 2022 9:46:54 VORM. hudson.remoting.jnlp.Main createEngine
INFO: Setting up agent: myslave
Aug. 30, 2022 9:46:54 VORM. hudson.remoting.Engine startEngine
INFO: Using Remoting version: 3046.v38db_38a_b_7a_86
Aug. 30, 2022 9:46:54 VORM. org.jenkinsci.remoting.engine.WorkDirManager initializeWorkDir
INFO: Using c:\remoting as a remoting work directory
Aug. 30, 2022 9:46:55 VORM. hudson.remoting.jnlp.Main$CuiListener status
INFO: WebSocket connection open
Aug. 30, 2022 9:46:55 VORM. hudson.remoting.jnlp.Main$CuiListener status
INFO: Connected
Aug. 30, 2022 9:50:40 VORM. hudson.remoting.jnlp.Main$CuiListener status
INFO: Read side closed
Aug. 30, 2022 9:50:40 VORM. hudson.remoting.jnlp.Main$CuiListener status
INFO: Read side closed
Aug. 30, 2022 9:50:40 VORM. hudson.remoting.jnlp.Main$CuiListener status
INFO: Terminated
Aug. 30, 2022 9:50:40 VORM. hudson.remoting.jnlp.Main$CuiListener status
INFO: Performing onReconnect operation.
Aug. 30, 2022 9:50:40 VORM. hudson.remoting.jnlp.Main$CuiListener status
INFO: onReconnect operation completed.
Aug. 30, 2022 9:50:40 VORM. hudson.remoting.jnlp.Main$CuiListener status
INFO: WebSocket connection open
Aug. 30, 2022 9:50:40 VORM. hudson.remoting.jnlp.Main$CuiListener status
INFO: Connected
Aug. 30, 2022 10:13:26 VORM. hudson.remoting.jnlp.Main$CuiListener status
INFO: Read side closed
Aug. 30, 2022 10:13:26 VORM. hudson.remoting.jnlp.Main$CuiListener status
INFO: Read side closed
Aug. 30, 2022 10:13:26 VORM. hudson.remoting.jnlp.Main$CuiListener status
INFO: Terminated
Aug. 30, 2022 10:13:27 VORM. hudson.remoting.jnlp.Main$CuiListener status
INFO: Performing onReconnect operation.
Aug. 30, 2022 10:13:27 VORM. hudson.remoting.jnlp.Main$CuiListener status
INFO: onReconnect operation completed.
Aug. 30, 2022 10:13:27 VORM. hudson.remoting.jnlp.Main$CuiListener status
INFO: WebSocket connection open
Aug. 30, 2022 10:13:27 VORM. hudson.remoting.jnlp.Main$CuiListener status
INFO: Connected
Aug. 30, 2022 10:21:48 VORM. hudson.remoting.jnlp.Main$CuiListener status
INFO: Read side closed
Aug. 30, 2022 10:21:53 VORM. hudson.remoting.jnlp.Main$CuiListener status
INFO: Read side closed
Aug. 30, 2022 10:21:57 VORM. hudson.remoting.jnlp.Main$CuiListener status
INFO: Terminated
Aug. 30, 2022 10:21:58 VORM. hudson.Launcher$RemoteLaunchCallable$1 join
INFO: Failed to synchronize IO streams on the channel hudson.remoting.Channel@54917ae3:myslave
hudson.remoting.ChannelClosedException: Channel "hudson.remoting.Channel@54917ae3:myslave": Remote call on myslave failed. The channel is closing down or has closed down
    at hudson.remoting.Channel.call(Channel.java:993)
    at hudson.remoting.Channel.syncIO(Channel.java:1732)
    at hudson.Launcher$RemoteLaunchCallable$1.join(Launcher.java:1411)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:566)
    at hudson.remoting.RemoteInvocationHandler$RPCRequest.perform(RemoteInvocationHandler.java:924)
    at hudson.remoting.RemoteInvocationHandler$RPCRequest.call(RemoteInvocationHandler.java:902)
    at hudson.remoting.RemoteInvocationHandler$RPCRequest.call(RemoteInvocationHandler.java:853)
    at hudson.remoting.UserRequest.perform(UserRequest.java:211)
    at hudson.remoting.UserRequest.perform(UserRequest.java:54)
    at hudson.remoting.Request$2.run(Request.java:376)
    at hudson.remoting.InterceptingExecutorService.lambda$wrap$0(InterceptingExecutorService.java:78)
    at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
    at hudson.remoting.Engine$1.lambda$newThread$0(Engine.java:125)
    at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: hudson.remoting.ChannelClosedException: Channel "hudson.remoting.Channel@54917ae3:myslave": channel is already closed
    at hudson.remoting.Engine$1AgentEndpoint.onClose(Engine.java:628)
    at io.jenkins.remoting.shaded.org.glassfish.tyrus.core.TyrusEndpointWrapper.onClose(TyrusEndpointWrapper.java:1241)
    at io.jenkins.remoting.shaded.org.glassfish.tyrus.core.TyrusWebSocket.onClose(TyrusWebSocket.java:110)
    at io.jenkins.remoting.shaded.org.glassfish.tyrus.core.ProtocolHandler.close(ProtocolHandler.java:481)
    at io.jenkins.remoting.shaded.org.glassfish.tyrus.core.TyrusWebSocket.close(TyrusWebSocket.java:244)
    at io.jenkins.remoting.shaded.org.glassfish.tyrus.core.TyrusWebSocket.close(TyrusWebSocket.java:254)
    at io.jenkins.remoting.shaded.org.glassfish.tyrus.core.TyrusRemoteEndpoint.close(TyrusRemoteEndpoint.java:480)
    at io.jenkins.remoting.shaded.org.glassfish.tyrus.core.TyrusSession.close(TyrusSession.java:220)
    at hudson.remoting.Engine$1AgentEndpoint$Transport.closeRead(Engine.java:661)
    at hudson.remoting.Channel.terminate(Channel.java:1074)
    at hudson.remoting.Channel$1.terminate(Channel.java:620)
    at hudson.remoting.AbstractByteBufferCommandTransport.terminate(AbstractByteBufferCommandTransport.java:314)
    at hudson.remoting.Engine$1AgentEndpoint.onClose(Engine.java:628)
    at io.jenkins.remoting.shaded.org.glassfish.tyrus.core.TyrusEndpointWrapper.onClose(TyrusEndpointWrapper.java:1241)
    at io.jenkins.remoting.shaded.org.glassfish.tyrus.core.TyrusWebSocket.onClose(TyrusWebSocket.java:110)
    at io.jenkins.remoting.shaded.org.glassfish.tyrus.core.frame.CloseFrame.respond(CloseFrame.java:112)
    at io.jenkins.remoting.shaded.org.glassfish.tyrus.core.ProtocolHandler.process(ProtocolHandler.java:819)
    at io.jenkins.remoting.shaded.org.glassfish.tyrus.client.TyrusClientEngine$TyrusReadHandler.handle(TyrusClientEngine.java:726)
    at io.jenkins.remoting.shaded.org.glassfish.tyrus.container.jdk.client.ClientFilter.processRead(ClientFilter.java:204)
    at io.jenkins.remoting.shaded.org.glassfish.tyrus.container.jdk.client.Filter.onRead(Filter.java:111)
    at io.jenkins.remoting.shaded.org.glassfish.tyrus.container.jdk.client.Filter.onRead(Filter.java:113)
    at io.jenkins.remoting.shaded.org.glassfish.tyrus.container.jdk.client.SslFilter.handleRead(SslFilter.java:402)
    at io.jenkins.remoting.shaded.org.glassfish.tyrus.container.jdk.client.SslFilter.processRead(SslFilter.java:365)
    at io.jenkins.remoting.shaded.org.glassfish.tyrus.container.jdk.client.Filter.onRead(Filter.java:111)
    at io.jenkins.remoting.shaded.org.glassfish.tyrus.container.jdk.client.Filter.onRead(Filter.java:113)
    at io.jenkins.remoting.shaded.org.glassfish.tyrus.container.jdk.client.TransportFilter$4.completed(TransportFilter.java:295)
    at io.jenkins.remoting.shaded.org.glassfish.tyrus.container.jdk.client.TransportFilter$4.completed(TransportFilter.java:279)
    at java.base/sun.nio.ch.Invoker.invokeUnchecked(Invoker.java:127)
    at java.base/sun.nio.ch.Invoker$2.run(Invoker.java:219)
    at java.base/sun.nio.ch.AsynchronousChannelGroupImpl$1.run(AsynchronousChannelGroupImpl.java:112)
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
    ... 1 more

Aug. 30, 2022 10:22:00 VORM. hudson.remoting.Request$2 run
INFO: Failed to send back a reply to the request UserRequest:UserRPCRequest:hudson.Launcher$RemoteProcess.join[](6): hudson.remoting.ChannelClosedException: Channel "hudson.remoting.Channel@54917ae3:myslave": channel is already closed
Aug. 30, 2022 10:22:02 VORM. hudson.remoting.jnlp.Main$CuiListener status
INFO: Performing onReconnect operation.
Aug. 30, 2022 10:22:02 VORM. hudson.remoting.jnlp.Main$CuiListener status
INFO: onReconnect operation completed.
Aug. 30, 2022 10:22:02 VORM. hudson.remoting.jnlp.Main$CuiListener status
INFO: WebSocket connection open
Aug. 30, 2022 10:22:02 VORM. hudson.remoting.jnlp.Main$CuiListener status
INFO: Connected

After falling back to 2360 (including all plug-ins) the issue is gone.