FishForMessageAsync deadlocks with actor that has async receive handler and testprobe.Tell

[SchiessMax]

Version Information
Akka.TestKit.Xunit2 1.5.15 and upwards (works with 1.5.14)

Describe the bug
FishForMessage in combination with tell on an actor with async receive handler that calls "Tell" on the test probe that triggered the handler.

To Reproduce
Steps to reproduce the behavior:

1. Execute Unittest with debugger:

using System;
using System.Threading.Tasks;
using Akka.Actor;
using Akka.TestKit.Xunit2;
using Xunit;

namespace CODESYS.CAS.TaskManager.UnitTests;

public class Foobar : TestKit
{
    private class AsyncActor : ReceiveActor
    {
        private readonly IActorRef _probe;

        public AsyncActor(IActorRef probe)
        {
            _probe = probe;
            ReceiveAnyAsync(async msg =>
            {
                _probe.Tell(msg);
                await Task.CompletedTask;
            });
        }
    }
    
    [Fact]
    public async Task Deadlock()
    {
        var probe = CreateTestProbe();
        var testee = Sys.ActorOf(Props.Create(() => new AsyncActor(probe)));
        var msg = 123;
        
        testee.Tell("foobar");
        testee.Tell(msg);
        
        await probe.FishForMessageAsync(m => m.Equals(msg), TimeSpan.FromDays(1));
    }
}

2. Unittest deadlocks
3. Pause debugger: unittest is deadlocked on _probe.Tell(msg);

Expected behavior
Unittest should pass - no deadlock should occur.

Actual behavior
The unittest deadlocked.

Environment
Windows, .net 8

[SchiessMax]

This was fixed with Version 1.5.19, I think with #7157
The unit test provided above now passes.