How to get a .Net Framework SignalR client to connect to .Net Core SignalR Server?

Question

SignalR Server:

IIS ASP.Net Core 8.0,

Microsoft.AspNetCore.SignalR 1.1.0,

Microsoft.AspNetCore.SignalR.Core 1.1.0,

Angular,

Javascript (Browser) successfully made SignalR connection

SignalR Client 1:

IIS ASP.NET 4.8,

Microsoft.AspNetCore.SignalR.Client 8.0.0.0,

Microsoft.AspNetCore.SignalR.Client.Core 8.0.0.0,

successfully made SignalR connection

SignalR Client 2:

Windows C# Desktop UI App .NET Framework 4.8,

Microsoft.AspNetCore.SignalR.Client 8.0.0.0,

Microsoft.AspNetCore.SignalR.Client.Core 8.0.0.0,

Failed to make SignalR connection.

Connection = new HubConnectionBuilder()

.WithUrl("http://localhost/QMOSRFactor/rfactor",

    options => {

        options.Transports = HttpTransportType.WebSockets;

    })

.WithAutomaticReconnect()

.Build();

await Connection.StartAsync();

For SignalR Client 2, after calling await Connection.StartAsync(), nothing happened. No error in Visual Studio Output. No exceptions throwed.

If I wrapped the above code in netstandard2.0 library. Reference this library in Client 2 project. Nothing happened. No error in Visual Studio Output. No exceptions.