How to produce single updates when batch editing in dynamic data

Question

Let me start by saying that I'm really new to both Reactive Extensions and DynamicData so i'm probably missing something really obvious here.

Aim: I want to calculate the profit (or loss) for some trades (similar to: https://dynamic-data.org/2014/11/22/trading-example-part-2-manage-market-data/) based on the new market prices. For simplicity lets say that all prices received in the last second are considered new.

My problem: Multiple update events occur for the same currencies in 1 sec (eg EURUSD) even if batch editing is used. Ideally i would only like to raise 1 event based on the latest available value to avoid doing unnecessary calculations.

My code so far:

Main.cs

using System.Reactive.Linq;
using DynamicData;


TickService tickService = new();

tickService.NewTicks
    .Connect()
    .Watch("EURUSD")
    .Subscribe(price => Console.WriteLine(price));

/*
 * In the actual project the prices come from an external system,
 * but that is irrelevant here 
 * so for the sake of simplicity I'm adding them manually (with a delay)
 * to TickService
 */
Task.Run(() =>
{
    for (int i = 0; i < 10; i++)
    {
        var newTicks = new List<Tick>() { new Tick() { Name = "EURUSD", Price = i, LastUpdate = DateTime.UtcNow } };
        tickService.AddTicks(newTicks);
        Console.WriteLine($"Added: i -> {i}");
        Thread.Sleep(250);
    }
});

Console.ReadLine();

Tick.cs

public class Tick
{
    public string Name { get; set; } = "";
    public double Price { get; set; }
    public DateTime LastUpdate { get; set; }

    public override string ToString()
    {
        return $"Name: {Name}, Price: {Price}, LastUpdate: {LastUpdate}";
    }
}

TickService.cs (Exposes an IObservableCache with the prices of the last second)

using DynamicData;

public class TickService
{
    private readonly SourceCache<Tick, string> _ticksCache = new(x => x.Name);
    public IObservableCache<Tick, string> NewTicks { get; }

    public TickService()
    {
        NewTicks = _ticksCache
             .Connect()
             .Filter(tick => tick.LastUpdate > DateTime.UtcNow - TimeSpan.FromSeconds(1))
             .Batch(TimeSpan.FromSeconds(1))
             .AsObservableCache();
    }

    public void AddTicks(ICollection<Tick> newTicks)
    {
        _ticksCache.Edit(innerCache => innerCache.AddOrUpdate(newTicks));
    }
}

The above code results in the below result:

Added: i -> 0
Added: i -> 1
Added: i -> 2
Added: i -> 3
Add, Key: EURUSD, Current: Name: EURUSD, Price: 0, LastUpdate: 14/03/2022 4:14:20 pm, Previous: <None>
Update, Key: EURUSD, Current: Name: EURUSD, Price: 1, LastUpdate: 14/03/2022 4:14:20 pm, Previous: Name: EURUSD, Price: 0, LastUpdate: 14/03/2022 4:14:20 pm
Update, Key: EURUSD, Current: Name: EURUSD, Price: 2, LastUpdate: 14/03/2022 4:14:21 pm, Previous: Name: EURUSD, Price: 1, LastUpdate: 14/03/2022 4:14:20 pm
Update, Key: EURUSD, Current: Name: EURUSD, Price: 3, LastUpdate: 14/03/2022 4:14:21 pm, Previous: Name: EURUSD, Price: 2, LastUpdate: 14/03/2022 4:14:21 pm
Added: i -> 4
Added: i -> 5
Added: i -> 6
Added: i -> 7
Update, Key: EURUSD, Current: Name: EURUSD, Price: 4, LastUpdate: 14/03/2022 4:14:21 pm, Previous: Name: EURUSD, Price: 3, LastUpdate: 14/03/2022 4:14:21 pm
Update, Key: EURUSD, Current: Name: EURUSD, Price: 5, LastUpdate: 14/03/2022 4:14:21 pm, Previous: Name: EURUSD, Price: 4, LastUpdate: 14/03/2022 4:14:21 pm
Update, Key: EURUSD, Current: Name: EURUSD, Price: 6, LastUpdate: 14/03/2022 4:14:22 pm, Previous: Name: EURUSD, Price: 5, LastUpdate: 14/03/2022 4:14:21 pm
Update, Key: EURUSD, Current: Name: EURUSD, Price: 7, LastUpdate: 14/03/2022 4:14:22 pm, Previous: Name: EURUSD, Price: 6, LastUpdate: 14/03/2022 4:14:22 pm
Added: i -> 8
Added: i -> 9
Update, Key: EURUSD, Current: Name: EURUSD, Price: 8, LastUpdate: 14/03/2022 4:14:22 pm, Previous: Name: EURUSD, Price: 7, LastUpdate: 14/03/2022 4:14:22 pm
Update, Key: EURUSD, Current: Name: EURUSD, Price: 9, LastUpdate: 14/03/2022 4:14:22 pm, Previous: Name: EURUSD, Price: 8, LastUpdate: 14/03/2022 4:14:22 pm

What i want is:

Added: i -> 0
Added: i -> 1
Added: i -> 2
Added: i -> 3
Update, Key: EURUSD, Current: Name: EURUSD, Price: 3, LastUpdate: 14/03/2022 4:14:21 pm, Previous: Name: EURUSD, Price: 2, LastUpdate: 14/03/2022 4:14:21 pm
Added: i -> 4
Added: i -> 5
Added: i -> 6
Added: i -> 7
Update, Key: EURUSD, Current: Name: EURUSD, Price: 7, LastUpdate: 14/03/2022 4:14:22 pm, Previous: Name: EURUSD, Price: 6, LastUpdate: 14/03/2022 4:14:22 pm
Added: i -> 8
Added: i -> 9
Update, Key: EURUSD, Current: Name: EURUSD, Price: 9, LastUpdate: 14/03/2022 4:14:22 pm, Previous: Name: EURUSD, Price: 8, LastUpdate: 14/03/2022 4:14:22 pm

Since i'm using batch editing I would expect only one one update event to produce every second for EURUSD. Any ideas/advice as to what I'm missing here?

Thank you