Disposal errors when navigating away from `Paint.razor` under some conditions

System.NullReferenceException: Object reference not set to an instance of an object.
   at Akka.Actor.ActorRefImplicitSenderExtensions.Tell(IActorRef receiver, Object message)
   at DrawTogether.Components.Pages.Paint.DisposeAsync() in C:\Repositories\Petabridge\DrawTogether.NET\src\DrawTogether\Components\Pages\Paint.razor:line 238
   at Microsoft.AspNetCore.Components.RenderTree.Renderer.<>c__DisplayClass93_0.<<Dispose>g__HandleAsyncExceptions|0>d.MoveNext()
--- End of stack trace from previous location ---
   at Microsoft.AspNetCore.Components.RenderTree.Renderer.<>c__DisplayClass93_0.<<Dispose>g__HandleAsyncExceptions|0>d.MoveNext()
--- End of stack trace from previous location ---
   at Microsoft.AspNetCore.Components.RenderTree.Renderer.DisposeAsync()
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngineScope.<DisposeAsync>g__Await|26_0(Int32 i, ValueTask vt, List`1 toDispose)
   at Microsoft.AspNetCore.Http.Features.RequestServicesFeature.<DisposeAsync>g__Awaited|9_0(RequestServicesFeature servicesFeature, ValueTask vt)
   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.HttpProtocol.<FireOnCompleted>g__ProcessEvents|242_0(HttpProtocol protocol, Stack`1 events)

Start in src/DrawTogether/Components/Pages/Paint.razor, especially DisposeAsync() at line 238, and inspect the actor message sent during component disposal. Reproduce navigation away from Paint.razor under the failing conditions and verify disposal completes without the NullReferenceException shown in the report.