Something in the test runs is racy here:

[JVM-Node2] - auto-down the other nodes and form new cluster with potentially new leader *** FAILED *** (32 milliseconds)
[JVM-Node2] Previous step failed (MultiNodeClusterSpec.scala:82)
[JVM-Node2] org.scalatest.exceptions.TestFailedException:
[JVM-Node2] at akka.cluster.MultiNodeClusterSpec$class.withFixture(MultiNodeClusterSpec.scala:82)
[JVM-Node3] - detect network partition and mark nodes on other side as unreachable *** FAILED *** (20 seconds, 926 milliseconds)
[JVM-Node3] java.lang.RuntimeException: barrier failed: after-2
[JVM-Node3] at akka.remote.testconductor.ClientFSM$$anonfun$4.applyOrElse(Player.scala:203)
[JVM-Node3] at akka.remote.testconductor.ClientFSM$$anonfun$4.applyOrElse(Player.scala:179)
[JVM-Node3] at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:37)
[JVM-Node3] at akka.actor.FSM$class.processEvent(FSM.scala:571)
[JVM-Node3] at akka.remote.testconductor.ClientFSM.akka$actor$LoggingFSM$$super$processEvent(Player.scala:142)
[JVM-Node3] at akka.actor.LoggingFSM$class.processEvent(FSM.scala:702)
[JVM-Node3] at akka.remote.testconductor.ClientFSM.processEvent(Player.scala:142)
[JVM-Node3] at akka.actor.FSM$class.akka$actor$FSM$$processMsg(FSM.scala:565)
[JVM-Node3] at akka.actor.FSM$$anonfun$receive$1.applyOrElse(FSM.scala:559)
[JVM-Node3] at akka.actor.ActorCell.receiveMessage(ActorCell.scala:394)
[JVM-Node3] at akka.actor.ActorCell.invoke(ActorCell.scala:369)
[JVM-Node3] at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:230)
[JVM-Node3] at akka.dispatch.Mailbox.run(Mailbox.scala:212)
[JVM-Node3] at akka.dispatch.ForkJoinExecutorConfigurator$MailboxExecutionTask.exec(AbstractDispatcher.scala:509)
[JVM-Node3] at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:262)
[JVM-Node3] at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:975)
[JVM-Node3] at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1478)
[JVM-Node3] at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:104)