Agents (swarm-client in use) go offline during job execution

00:00:00.002 [EnvInject] - Loading node environment variables.
00:08:49.244 FATAL: java.nio.channels.ClosedChannelException
00:08:49.249 java.nio.channels.ClosedChannelException
00:08:49.249 Also: hudson.remoting.Channel$CallSiteStackTrace: Remote call to JNLP4-connect connection from ************/************
00:08:49.249 at hudson.remoting.Channel.attachCallSiteStackTrace(Channel.java:1737)
00:08:49.249 at hudson.remoting.Request.call(Request.java:197)
00:08:49.249 at hudson.remoting.Channel.call(Channel.java:951)
00:08:49.249 at hudson.FilePath.act(FilePath.java:1104)
00:08:49.249 at org.jenkinsci.plugins.envinject.service.EnvironmentVariablesNodeLoader.gatherEnvVarsForNode(EnvironmentVariablesNodeLoader.java:64)
00:08:49.249 at org.jenkinsci.plugins.envinject.EnvInjectListener.loadEnvironmentVariablesNode(EnvInjectListener.java:80)
00:08:49.249 at org.jenkinsci.plugins.envinject.EnvInjectListener.setUpEnvironment(EnvInjectListener.java:44)
00:08:49.249 at hudson.model.AbstractBuild$AbstractBuildExecution.createLauncher(AbstractBuild.java:542)
00:08:49.249 at hudson.model.AbstractBuild$AbstractBuildExecution.run(AbstractBuild.java:462)
00:08:49.249 at hudson.model.Run.execute(Run.java:1727)
00:08:49.249 at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:43)
00:08:49.249 at hudson.model.ResourceController.execute(ResourceController.java:97)
00:08:49.249 at hudson.model.Executor.run(Executor.java:429)
00:08:49.249 Caused: hudson.remoting.RequestAbortedException
00:08:49.249 at hudson.remoting.Request.abort(Request.java:335)
00:08:49.249 at hudson.remoting.Channel.terminate(Channel.java:1034)
00:08:49.249 at org.jenkinsci.remoting.protocol.impl.ChannelApplicationLayer.onReadClosed(ChannelApplicationLayer.java:208)
00:08:49.249 at org.jenkinsci.remoting.protocol.ApplicationLayer.onRecvClosed(ApplicationLayer.java:222)
00:08:49.249 at org.jenkinsci.remoting.protocol.ProtocolStack$Ptr.onRecvClosed(ProtocolStack.java:832)
00:08:49.249 at org.jenkinsci.remoting.protocol.FilterLayer.onRecvClosed(FilterLayer.java:287)
00:08:49.250 at org.jenkinsci.remoting.protocol.impl.SSLEngineFilterLayer.onRecvClosed(SSLEngineFilterLayer.java:172)
00:08:49.250 at org.jenkinsci.remoting.protocol.ProtocolStack$Ptr.onRecvClosed(ProtocolStack.java:832)
00:08:49.250 at org.jenkinsci.remoting.protocol.NetworkLayer.onRecvClosed(NetworkLayer.java:154)
00:08:49.250 at org.jenkinsci.remoting.protocol.impl.NIONetworkLayer.ready(NIONetworkLayer.java:179)
00:08:49.250 at org.jenkinsci.remoting.protocol.IOHub$OnReady.run(IOHub.java:789)
00:08:49.250 at jenkins.util.ContextResettingExecutorService$1.run(ContextResettingExecutorService.java:28)
00:08:49.250 at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
00:08:49.250 at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
00:08:49.250 at java.lang.Thread.run(Thread.java:748)
00:08:49.254 ERROR: Step ?Delete workspace when build is done? failed: no workspace for docker/***************-build #30
00:08:49.254 Finished: FAILURE

Java version: 8

Jenkins and build agents running in docker