(Blazor-server-side / SignalR / Net6) HubConnectionContext loses user in HttpContext the second time it's called

I am trying to send a message with SignalR to a specific user.
I implemented the default project authentication with Blazor Server side and Net6.
I can log in / log out / register.
I implemented the IUSerIdProvider Interface to get the UserId.
The first time I launch the app, I can retrieved the user (from connection.GetHttpContext(); or connection.User.FindFirstValue(ClaimTypes.Name); but when I navigate to an other page and call the hub again, the HubConnectionContext loses my User and all his informations.
If I force the id with a constant string it works but why do I lose the informations the second time ? I don't know if I need to use cookies because the first time I have informations.

// CustomUserIdProvider.cs
public class CustomUserIdProvider : IUserIdProvider
  {
    public string? GetUserId(HubConnectionContext connection)
    {
      var httpContext = connection.GetHttpContext();
      var userId = connection.User.FindFirstValue(ClaimTypes.Name);

      if (string.IsNullOrWhiteSpace(userId))
        return string.Empty;

      return userId;
    }
  }

// Program.cs
-----
builder.Services.AddSingleton<IUserIdProvider, CustomUserIdProvider>();
-----
app.UseAuthentication();
app.UseAuthorization();

// SignalR.razor (where I test to receive / send a message and here I lost the informations)

protected override async Task OnInitializedAsync()
{
        hubConnection = new HubConnectionBuilder()
            .WithUrl(NavigationManager.ToAbsoluteUri("/notifyhub"))
        .Build();
        hubConnection.On<int, string>("ReceiveMessage", (id, message) =>
    {
        var encodedMsg = $"{id}: {message}";
        InvokeAsync(StateHasChanged);
    });

        await hubConnection.StartAsync();
}
private async Task Send()
{
        if (hubConnection is not null)
        {
            var authState = await AuthenticationStateProvider.GetAuthenticationStateAsync();
            var user = authState.User;
            authMessage = $"{user.Identity.Name} is authenticated.";
            claims = user.Claims;
            surnameMessage =
                $"Surname: {user.FindFirst(c => c.Type == ClaimTypes.Surname)?.Value}";
            await hubConnection.SendAsync("Send", user.Identity.Name, 1, "Message envoyé");
        }
}