Issue with Akka Futures in CF Buildpack cflinuxfs3 with java-buildpack.git#v4.16.1

We recently upgraded the CF (Cloud Foundry) buildpack from cflinuxfs2 to cflinuxfs3. This comes with java buildpack changes from java-buildpack.git#v4.8 to java-buildpack.git#v4.16.1. Java version in the CF container changed from 1.8.0_162-b12 to 1.8.0_192-b12.

After this upgrade, we are facing a strange issue with Akka Futures. Though the multiple requests get submitted to Akka Future simultaneously, execution of the requests in the Future happens sequentially. The calling point is not blocked, but the Future execution for the second request is blocked till the completion of the first Future request execution.

Sample output in cflinuxfs2: (both requests get executed simultaneously)
Creating…one
future request received:one
Creating…two
future request received:two
future request finished:one
future request finished:two
success- one
success- two

Sample output in cflinuxfs3: (Both requests get submitted simultaneously but execution happens sequentially)
Creating…one
future request received:one
Creating…two
future request finished:one
success- one
future request received:two
future request finished:two
success- two

Sample code:

  def testFuture(id: String): Future[Boolean] = Future {
    println("future request received:" + id)
    Thread.sleep(10000)
    println("future request finished:" + id)
    true
  }
 
  def retValueValidation(id: String, retValue: Future[Boolean]) {
    retValue.onComplete {
      case scala.util.Success(true) =>
        println("success- " + id)
      case _ =>
        println("fail- one")
    }
  }
 
  println("Creating...one")
  val retValue = testFuture("one")
  retValueValidation("one", retValue)
 
  println("Creating...two")
  val retValue1 = testFuture("two")
  retValueValidation("two", retValue1)