Warning log event is filtered but never shows up in the actual log

[brah-mcdude]

I created a repository to reproduce this issue.

https://github.com/brah-mcdude/MyCompany.Akka.TestKit

As can be seen in the log, I received mostly debug messages and one info message. But no warning messages.
But the Predicate filters error and warnings.

When debugging, I saw that a warning message is generated. But it is never displayed in the log.

Here is the debug-watch warning log-event that is filtered:

[WARNING][01/17/2023 12:01:58.180][Thread 0032][akka://test/user/$a] Unhandled message from [akka://test/system/testActor1#139620980]: hi

Here is the entire log:

MyCompany.Akka.TestKit.ExpectLogNoWarningsNorErrorsAsyncSpecs.ExpectLogNoWarningsNorErrorsAsync_should_succeed_with_unhandled_message
   Source: ExpectLogNoWarningsNorErrorsAsyncSpecs.cs line 34
   Duration: 455 ms

  Message: 
Received 1 message too many. Expected 0 messages but received 1 that matched filter [Custom]
Expected: True
Actual:   False

  Stack Trace: 
XunitAssertions.Fail(String format, Object[] args)
InternalEventFilterApplier.InterceptAsync[T](Func`1 func, ActorSystem system, Nullable`1 timeout, Nullable`1 expectedOccurrences, MatchedEventHandler matchedEventHandler, CancellationToken cancellationToken)
InternalEventFilterApplier.InternalExpectAsync(Func`1 actionAsync, ActorSystem actorSystem, Int32 expectedCount, Nullable`1 timeout, CancellationToken cancellationToken)
InternalEventFilterApplier.ExpectAsync(Int32 expectedCount, Func`1 actionAsync, Nullable`1 timeout, CancellationToken cancellationToken)
TestKitBaseExtensions.ExpectLogNoWarningsNorErrorsAsync(TestKit x, Func`1 actionAsync) line 7
ExpectLogNoWarningsNorErrorsAsyncSpecs.ExpectLogNoWarningsNorErrorsAsync_should_succeed_with_unhandled_message() line 36
--- End of stack trace from previous location ---

  Standard Output: 
[DEBUG][01/17/2023 11:21:43.293][Thread 0012][EventStream] subscribing [akka://test/system/log-test#1262325061] to channel Akka.Event.LogEvent
[DEBUG][01/17/2023 11:21:43.293][Thread 0029][EventStreamUnsubscriber] watching [akka://test/system/log-test#1262325061] in order to unsubscribe from EventStream when it terminates
[DEBUG][01/17/2023 11:21:43.298][Thread 0012][akka://test/system/log-test] now watched by [akka://test/system/EventStreamUnsubscriber-1#977311273]
[DEBUG][01/17/2023 11:21:43.338][Thread 0028][akka://test/user] now supervising akka://test/user/$a
[DEBUG][01/17/2023 11:21:43.340][Thread 0009][akka://test/user/$a] Started (MyCompany.Akka.TestKit.SomeActor)
[DEBUG][01/17/2023 11:21:43.341][Thread 0033][akka://test/user/$a] Unhandled message from akka://test/system/testActor1 : hi
[INFO][01/17/2023 11:21:43.344][Thread 0009][akka://test/user/$a] Message [String] from [akka://test/system/testActor1#1271982917] to [akka://test/user/$a#1968059670] was unhandled. [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'.
[DEBUG][01/17/2023 11:21:43.385][Thread 0017][CoordinatedShutdown (akka://test)] Performing phase [before-service-unbind] with [0] tasks.
[DEBUG][01/17/2023 11:21:43.386][Thread 0009][CoordinatedShutdown (akka://test)] Performing phase [service-unbind] with [0] tasks.
[DEBUG][01/17/2023 11:21:43.386][Thread 0031][CoordinatedShutdown (akka://test)] Performing phase [service-requests-done] with [0] tasks.
[DEBUG][01/17/2023 11:21:43.386][Thread 0009][CoordinatedShutdown (akka://test)] Performing phase [service-stop] with [0] tasks.
[DEBUG][01/17/2023 11:21:43.386][Thread 0035][CoordinatedShutdown (akka://test)] Performing phase [before-cluster-shutdown] with [0] tasks.
[DEBUG][01/17/2023 11:21:43.386][Thread 0035][CoordinatedShutdown (akka://test)] Performing phase [cluster-sharding-shutdown-region] with [0] tasks.
[DEBUG][01/17/2023 11:21:43.386][Thread 0035][CoordinatedShutdown (akka://test)] Performing phase [cluster-leave] with [0] tasks.
[DEBUG][01/17/2023 11:21:43.386][Thread 0035][CoordinatedShutdown (akka://test)] Performing phase [cluster-exiting] with [0] tasks.
[DEBUG][01/17/2023 11:21:43.386][Thread 0035][CoordinatedShutdown (akka://test)] Performing phase [cluster-exiting-done] with [0] tasks.
[DEBUG][01/17/2023 11:21:43.386][Thread 0035][CoordinatedShutdown (akka://test)] Performing phase [cluster-shutdown] with [0] tasks.
[DEBUG][01/17/2023 11:21:43.386][Thread 0035][CoordinatedShutdown (akka://test)] Performing phase [before-actor-system-terminate] with [0] tasks.
[DEBUG][01/17/2023 11:21:43.399][Thread 0035][CoordinatedShutdown (akka://test)] Performing phase [actor-system-terminate] with [1] tasks: [terminate-system]
[DEBUG][01/17/2023 11:21:43.401][Thread 0035][ActorSystem(test)] System shutdown initiated
[DEBUG][01/17/2023 11:21:43.407][Thread 0009][EventStream] unsubscribing [akka://test/system/deadLetterListener#325587917] from all channels
[DEBUG][01/17/2023 11:21:43.408][Thread 0030][EventStreamUnsubscriber] unwatching [akka://test/system/deadLetterListener#325587917] since has no subscriptions
[DEBUG][01/17/2023 11:21:43.408][Thread 0027][akka://test/user] Stopping
[DEBUG][01/17/2023 11:21:43.421][Thread 0032][akka://test/user/$a] Stopped
[DEBUG][01/17/2023 11:21:43.422][Thread 0024][akka://test/user] Stopped
[DEBUG][01/17/2023 11:21:43.422][Thread 0009][akka://test/system/deadLetterListener] Stopped
[DEBUG][01/17/2023 11:21:43.423][Thread 0025][akka://test/system] received AutoReceiveMessage <Terminated>: [akka://test/user] - ExistenceConfirmed=True
[DEBUG][01/17/2023 11:21:43.426][Thread 0025][EventStream] subscribing [akka://all-systems/] to channel Akka.Event.Debug
[DEBUG][01/17/2023 11:21:43.426][Thread 0028][EventStreamUnsubscriber] watching [akka://all-systems/] in order to unsubscribe from EventStream when it terminates
[DEBUG][01/17/2023 11:21:43.427][Thread 0028][EventStreamUnsubscriber] watching [akka://all-systems/] in order to unsubscribe from EventStream when it terminates
[DEBUG][01/17/2023 11:21:43.426][Thread 0025][EventStream] subscribing [akka://all-systems/] to channel Akka.Event.Info
[DEBUG][01/17/2023 11:21:43.428][Thread 0028][EventStreamUnsubscriber] watching [akka://all-systems/] in order to unsubscribe from EventStream when it terminates
[DEBUG][01/17/2023 11:21:43.428][Thread 0025][EventStream] subscribing [akka://all-systems/] to channel Akka.Event.Warning
[DEBUG][01/17/2023 11:21:43.429][Thread 0025][EventStream] subscribing [akka://all-systems/] to channel Akka.Event.Error
[DEBUG][01/17/2023 11:21:43.429][Thread 0028][EventStreamUnsubscriber] watching [akka://all-systems/] in order to unsubscribe from EventStream when it terminates
[DEBUG][01/17/2023 11:21:43.430][Thread 0025][EventStream] Shutting down: StandardOutLogger started
[DEBUG][01/17/2023 11:21:43.431][Thread 0025][EventStream] unsubscribing [akka://test/system/log1-TestEventListener#1980956586] from all channels
[DEBUG][01/17/2023 11:21:43.432][Thread 0025][EventStream] All default loggers stopped
[DEBUG][01/17/2023 11:21:43.432][Thread 0023][EventStreamUnsubscriber] unwatching [akka://test/system/log1-TestEventListener#1980956586] since has no subscriptions
[DEBUG][01/17/2023 11:21:43.434][Thread 0031][akka://test/system/log1-TestEventListener] Stopped
[DEBUG][01/17/2023 11:21:43.435][Thread 0025][akka://test/system/testActor1] Stopped

[brah-mcdude]

I opened a new bug report: #6354.