eventuous: Using MapDiscoveredCommands with multiple aggregates results in error 'No handler found for command Object '

Describe the bug In a ASP NET Web Application, app.MapDiscoveredCommands() is not working as expected. All correctly registered commands are found but all are failing on execution with error

{
  "type": "CommandHandlerNotFound`1",
  "title": "No handler found for command Object",
  "status": 500,
  "detail": "Eventuous.Exceptions+CommandHandlerNotFound`1[System.Object]: No handler found for command Object"
}

To Reproduce See attached solution TestEventuous.zip with the following structure:

The solution contains Api, Application and Domain projects with commands for Car (StartEngine) and Train (OpenDoors) and the corresponding CommandServices.

[AggregateCommands<Car>]
public static class CarCommands
{
    [HttpCommand(Route = "car/start-engine")]
    public sealed record StartEngine
    {
        public required string CarId { get; init; }
    }
}

[AggregateCommands<Train>]
public static class TrainCommands
{
    [HttpCommand(Route = "train/open-doors")]
    public sealed record OpenDoors
    {
        public required string TrainId { get; init; }
    }
}

public sealed class CarService : CommandService<Car, CarState, CarId>
{
    public CarService(IAggregateStore? store, AggregateFactoryRegistry? factoryRegistry = null, StreamNameMap? streamNameMap = null, TypeMapper? typeMap = null)
        : base(store, factoryRegistry, streamNameMap, typeMap)
    {
        On<CarCommands.StartEngine>()
            .GetId(_ => new CarId(Guid.NewGuid().ToString()))
            .Act((car, _) => car.StartEngine());
    }
}

public sealed class TrainService : CommandService<Train, TrainState, TrainId>
{
    public TrainService(IAggregateStore? store, AggregateFactoryRegistry? factoryRegistry = null, StreamNameMap? streamNameMap = null, TypeMapper? typeMap = null)
        : base(store, factoryRegistry, streamNameMap, typeMap)
    {
        On<TrainCommands.OpenDoors>()
            .GetId(_ => new TrainId(Guid.NewGuid().ToString()))
            .Act((Train, _) => Train.OpenDoors());
    }
}

Running the application displays swagger with two endpoint car/start-engine and train/open-doors. Executing those endpoints yields the error described.

When changing app.MapDiscoveredCommands(typeof(ApplicationModule).Assembly); to app.MapDiscoveredCommands<Car>(typeof(ApplicationModule).Assembly); then car command is working as expected (but not train, but that is wanted, as described in the docs)

Expected behavior All discovered commands should reach their corresponding handler.

Screenshots