Ask can't find temporary actor inside async context

[Aaronontheweb]

Version: 1.4.4

The following code produces an AskTimeoutException:

public async Task ConsistentHashingPoolRoutersShouldWorkAsExpectedWithHashMapping()
        {
            var poolRouter =
                Sys.ActorOf(Props.Create(() => new ReporterActor(TestActor)).WithRouter(new ConsistentHashingPool(5,
                        msg =>
                        {
                            if (msg is IConsistentHashable c)
                                return c.ConsistentHashKey;
                            return msg;
                        })),
                    "router1");

            // use some auto-received messages to ensure that those still work
            var numRoutees = (await poolRouter.Ask<Routees>(new GetRoutees(), TimeSpan.FromSeconds(2))).Members.Count();

            // establish association between ActorSystems
            var sys2Probe = CreateTestProbe(Sys2);
            var secondActor = Sys.ActorOf(act => act.ReceiveAny((o, ctx) => ctx.Sender.Tell(o)), "foo");

            Sys2.ActorSelection(new RootActorPath(Sys1Address) / "user" / secondActor.Path.Name).Tell("foo", sys2Probe);
            sys2Probe.ExpectMsg("foo");

            // have ActorSystem2 message it via tell
            var sel = Sys2.ActorSelection(new RootActorPath(Sys1Address) / "user" / "router1");
            sel.Tell(new HashableString("foo"));
            ExpectMsg<HashableString>(str => str.Str.Equals("foo"));

            // have ActorSystem2 message it via Ask
            sel.Ask(new Identify("bar2"), TimeSpan.FromSeconds(3)).PipeTo(sys2Probe);
            var remoteRouter = sys2Probe.ExpectMsg<ActorIdentity>(x => x.MessageId.Equals("bar2"), TimeSpan.FromSeconds(5)).Subject;

            var s2Actor = Sys2.ActorOf(act =>
            {
                act.ReceiveAny((o, ctx) =>
                    sel.Ask<ActorIdentity>(new Identify(o), TimeSpan.FromSeconds(3)).PipeTo(sys2Probe));
            });
            s2Actor.Tell("hit");
            sys2Probe.ExpectMsg<ActorIdentity>(x => x.MessageId.Equals("hit"), TimeSpan.FromSeconds(5));
        }

Specifically, this line:

// have ActorSystem2 message it via Ask
sel.Ask(new Identify("bar2"), TimeSpan.FromSeconds(3)).PipeTo(sys2Probe);
var remoteRouter = sys2Probe.ExpectMsg<ActorIdentity>(x => x.MessageId.Equals("bar2"), TimeSpan.FromSeconds(5)).Subject;

From the logs:

DEBUG][4/22/2020 9:11:36 PM][Thread 0042][LocalActorRefProvider(akka://test2)] Resolve of path sequence [/temp/f] failed
[INFO][4/22/2020 9:11:36 PM][Thread 0009][akka://test2/temp/f] Message [ActorIdentity] from akka.tcp://test@localhost:55844/user/router1 to akka://test2/temp/f was not delivered. [1] dead letters encountered .This logging can be turned off or adjusted with configuration settings 'akka.log-dead-letters' and 'akka.log-dead-letters-during-shutdown'.

The issue might be with running two ActorSystem instances in the same context, but this is 100% reproducible.