Activity input with complex types ends up as JSON Elements

[vegar]

As part of an orchestration, I have an activity to store some metadata to a database before awaiting an external event.

The activity is defined like this:

[DurableTask("CreateAwaitedEvent")]
public class CreateAwaitedEventActivity : TaskActivity<CreateAwaitedEventActivityInput, Guid>
{
    public CreateAwaitedEventActivity(AppDbContext dbContext) { ... }

    public override async Task<Guid> RunAsync(TaskActivityContext context, CreateAwaitedEventActivityInput input) { ... }
}

public record CreateAwaitedEventActivityInput(EventType EventType, string OrchestratorId, Dictionary<string, object> Properties);

The activity is called from the orchestrator:

var eventId = await context.CallCreateAwaitedEventAsync(new CreateAwaitedEventActivityInput(EventType.ConfirmDeploymentPlan, context.InstanceId, new Dictionary<string, object>()
{
  {"ComponentContext", input},
  {"PlanResult", planResult}
}));

Inside of the activity, the objects added to the dictionary has changed from it's original type to JsonElements, as shown in the following picture:

Is this a bug or expected behavior?
Is the behavior documented anywhere?
Can it be prevented?

The problem might be related to issue #36 which was marked solved back in 2022.