Exception thrown during serialization is not visible

SignalRSerializingBugRepro.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.SignalR;
using Microsoft.AspNetCore.SignalR.Client;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;

namespace SignalRRepro
{
	public class Startup
	{
		public void ConfigureServices(IServiceCollection services)
		{
			services.AddSignalR();
			services.AddHostedService<HubClient>();
		}

		public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
		{
			app.UseRouting();

			app.UseEndpoints(endpoints =>
			{
				endpoints.MapHub<MyHub>("myhub");
			});
		}
	}

	public class MyClass
	{
		public string Value
		{
			get => throw new Exception("My custom exception");
		}
	}

	internal class MyHub : Hub
	{
		private readonly ILogger _logger;

		public MyHub(ILogger<MyHub> logger)
		{
			_logger = logger ?? throw new ArgumentNullException(nameof(logger));
		}

		public MyClass DoWork()
		{
			return new MyClass();
		}

		public override Task OnDisconnectedAsync(Exception exception)
		{
			if (exception is null)
			{
				_logger.LogInformation("Client disconnected");
			}
			else
			{
				_logger.LogWarning(exception, "Client disconnected with an error");
			}

			return Task.CompletedTask;
		}

	}

	internal class HubClient : BackgroundService
	{
		private readonly ILogger _logger;

		public HubClient(ILogger<HubClient> logger)
		{
			_logger = logger ?? throw new ArgumentNullException(nameof(logger));
		}

		protected override async Task ExecuteAsync(CancellationToken stoppingToken)
		{
			try
			{
				await using var connection = new HubConnectionBuilder()
					.WithUrl("http://localhost:5000/myhub")
					.Build();

				await Task.Delay(1000);
				await connection.StartAsync();
				var result = await connection.InvokeAsync<MyClass>("DoWork");
				_logger.LogInformation("Client succeeded");
			}
			catch (Exception ex)
			{
				_logger.LogError(ex, "Client failed");
			}
		}
	}

}