HubCallerContext User object empty

I'm beginner with SignalR Hub and I've this problem.

When "OnConnectedAsync" is called the object Context.User is always empty.

This is the method:

[Authorize]
public override async Task OnConnectedAsync()
{
    if(Context.User.Identity.IsAuthenticated)
    {
        await base.OnConnectedAsync();
        Errore er = _g.AggiungiConnessione(Context.User.Identity.Name, Context);
    }
}

the authentication is configurated like this:

services.AddAuthentication(options =>
{
    options.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
    options.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;
}).AddJwtBearer(options =>
{
    options.Events = new JwtBearerEvents
    {
        OnMessageReceived = context =>
        {
            var path = context.HttpContext.Request.Path;

            if (!path.StartsWithSegments("/chatHub")) 
                return Task.CompletedTask;

            var accessToken = context.Request.Headers[HeaderNames.Authorization];
            if (!string.IsNullOrWhiteSpace(accessToken) && context.Scheme.Name == 
                JwtBearerDefaults.AuthenticationScheme)
            {
                context.Token = accessToken;
            }

            return Task.CompletedTask;
        }
    };
});

the HubConnection is declared like this:

if (user.Identity.IsAuthenticated)
{
    hubConnection = new 
 HubConnectionBuilder().WithAutomaticReconnect().WithUrl(navmanager.ToAbsoluteUri("/chatHub"), 
    (opts) =>
    {
        opts.HttpMessageHandlerFactory = (message) =>
            {
                if (message is HttpClientHandler clientHandler)
                {
                    clientHandler.ServerCertificateCustomValidationCallback += (sender, 
                    certificate, chain, sslPolicyErrors) => { return true; };
                }
                return message;
             };
             opts.AccessTokenProvider = async () => await Task.FromResult(user.Identity.Name);
     }
}

any suggestions?