Invoking an async method by reflection does not always work

Question

I'm having trouble with existing code that does not work anymore.

Basically, I'm invoking an asynchronous method by reflection:

Sometimes it does work, sometimes it does not.

The code comes from here

using (var scope = this.services.CreateScope())
{
    var workerType = workOrder
        .GetType()
        .GetInterfaces()
        .First(t => t.IsConstructedGenericType && t.GetGenericTypeDefinition() == typeof(IBackgroundWorkOrder<,>))
        .GetGenericArguments()
        .Last();

    var worker = scope.ServiceProvider
        .GetRequiredService(workerType);

    var task = (Task)workerType
        .GetMethod("DoWork")
        .Invoke(worker, new object[] { workOrder, this.shutdown.Token });

    await task.ContinueWith(HandleTask, TaskScheduler.Current).ConfigureAwait(continueOnCapturedContext: false);
}

In debug mode, If I set a breakpoint ont the last await, and in the async method that should be invoked, I can see than the task is already faulted before the method is called.

What could be wrong here? Any Ideas?