I am trying to create a Remote PowerShell (RPS) that will form connection between machines to execute RPS Commands. I have this following example setup "HostPC with C# console application (that executes RPS) to form connection between two Remote PCs"

The following link (Certificate (password-less) based authentication in WinRM) was found from one of the comments in answer in separate question. From the article, the author presented with high-level approach to create Certificate (password-less) based authentication in WinRM and they are the following:

1. Configure SSL connectivity to winrm on the endpoint
2. Generate a user certificate used for authentication
3. Enable Certificate authentication on the endpoint. Its disabled by default for server auth and enabled on the client side.
4. Add the user certificate and its issuing CA certificate to the certificate store of the endpoint
5. Create a user mapping in winrm with the thumbprint of the issuing certificate on the endpoint.

So what I have done are the following:

Certificate Authentication Setup:

1. Configured WinRM to work with HTTPS in Remote PCs
2. Created Client Certificate in HostPC
3. Exported the Client Certificate and imported it on the Remote PCs
4. Configured WinRM to enable the Certificate Authentication on the Remote PCs
5. Created Certificates in each Remote PC
6. Binded the Remote PC certificates to the HTTPS Listener
7. Created the winrm user mapping using the HostPC certificate in each Remote PC

Configured WinRM to work with HTTPS

winrm quickconfig -transport:https

Certificate Creation

New-SelfSignedCertificate `
  -DnsName <PCName> `
  -CertStoreLocation <CertificateLocation> `
  -KeyLength 2048 `
  -NotAfter (Get-Date).AddYears(xx) `
  -TextExtension @("2.5.29.37={text}<OID Purpose>")

Certificate Authentication

winrm set winrm/config/service/auth @{Certificate="true"}

Binding Certificate to HTTPS Listener

winrm create winrm/config/Listener?Address=*+Transport=HTTPS "@{Hostname=<RemotePCName>";CertificateThumbprint=<RemotePC Certificate Thumbprint>"}"

User Mapping

New-Item -Path WSMan:\localhost\ClientCertificate `
         -Subject '<HostPCName>' `
         -URI * `
         -Issuer <HostPC Certificate Thumbprint> `
         -Credential (Get-Credential)

C# Application Side:

<Program.cs Section>
connectionInfo = new WSManConnectionInfo(new Uri($"https://{MachineName}:5986/wsman"),
"http://schemas.microsoft.com/powershell/Microsoft.PowerShell", (PSCredential?)null);
connectionInfo.CertificateThumbprint = CertLoader.CertificateLoad(MachineName);

<CertificateLoader>
        public string? CertificateLoad(string? machinename)
        {
            X509Store? store = null;
            X509Certificate2? cert = null;

            try
            {
                if(machinename == null)
                {
                    <Console Write Message Error>
                    
                    return null;
                }

                store = new X509Store(<CertificateLocation>, <CertificateLocationType>);
                store.Open(OpenFlags.ReadOnly);
                cert = store.Certificates.OfType<X509Certificate2>().FirstOrDefault(c =>
                            c.Subject.Contains($"{machinename}", StringComparison.OrdinalIgnoreCase));
                store.Close();
                return cert.Thumbprint;
            }
            catch (Exception ex)
            {
                <Console Write Message Error>
                return null;
            }
        }

<In Separate Class>
<PowerShell Execution Function>
using (runspace = RunspaceFactory.CreateRunspace(connectioninfo))
{
   runspace.Open();
   using (pipeline = PowerShell.Create())
   {

However, It keeps on failing when it gets to the using (runspace = RunspaceFactory.CreateRunspace(connectioninfo)) with the following error message:

Exception Message: System.Management.Automation.PSInvalidOperationException: The WS-Management service cannot find the certificate that was requested.
   at System.Management.Automation.Remoting.Client.WSManClientSessionTransportManager.Initialize(Uri connectionUri, WSManConnectionInfo connectionInfo)
   at System.Management.Automation.Remoting.Client.WSManClientSessionTransportManager..ctor(Guid runspacePoolInstanceId, WSManConnectionInfo connectionInfo, PSRemotingCryptoHelper cryptoHelper, String sessionName)
   at System.Management.Automation.Runspaces.WSManConnectionInfo.CreateClientSessionTransportManager(Guid instanceId, String sessionName, PSRemotingCryptoHelper cryptoHelper)
   at System.Management.Automation.Remoting.ClientRemoteSessionDSHandlerImpl..ctor(ClientRemoteSession session, PSRemotingCryptoHelper cryptoHelper, RunspaceConnectionInfo connectionInfo, URIDirectionReported uriRedirectionHandler)
   at System.Management.Automation.Remoting.ClientRemoteSessionImpl..ctor(RemoteRunspacePoolInternal rsPool, URIDirectionReported uriRedirectionHandler)
   at System.Management.Automation.Internal.ClientRunspacePoolDataStructureHandler.CreateClientRemoteSession(RemoteRunspacePoolInternal rsPoolInternal)
   at System.Management.Automation.Internal.ClientRunspacePoolDataStructureHandler..ctor(RemoteRunspacePoolInternal clientRunspacePool, TypeTable typeTable)
   at System.Management.Automation.Runspaces.Internal.RemoteRunspacePoolInternal.CreateDSHandler(TypeTable typeTable)
   at System.Management.Automation.Runspaces.Internal.RemoteRunspacePoolInternal..ctor(Int32 minRunspaces, Int32 maxRunspaces, TypeTable typeTable, PSHost host, PSPrimitiveDictionary applicationArguments, RunspaceConnectionInfo connectionInfo, String name)
   at System.Management.Automation.Runspaces.RunspacePool..ctor(Int32 minRunspaces, Int32 maxRunspaces, TypeTable typeTable, PSHost host, PSPrimitiveDictionary applicationArguments, RunspaceConnectionInfo connectionInfo, String name)
   at System.Management.Automation.RemoteRunspace..ctor(TypeTable typeTable, RunspaceConnectionInfo connectionInfo, PSHost host, PSPrimitiveDictionary applicationArguments, String name, Int32 id)
   at System.Management.Automation.Runspaces.RunspaceFactory.CreateRunspace(RunspaceConnectionInfo connectionInfo, PSHost host, TypeTable typeTable, PSPrimitiveDictionary applicationArguments, String name)
   at System.Management.Automation.Runspaces.RunspaceFactory.CreateRunspace(RunspaceConnectionInfo connectionInfo, PSHost host, TypeTable typeTable)
   at System.Management.Automation.Runspaces.RunspaceFactory.CreateRunspace(PSHost host, RunspaceConnectionInfo connectionInfo)
   at System.Management.Automation.Runspaces.RunspaceFactory.CreateRunspace(RunspaceConnectionInfo connectionInfo)

In addition, (I can't remember what I have done) Before I got the error above, it failed in the runspace.Open(); part with the following message:

System.Management.Automation.Remoting.PSRemotingTransportException: 'Connecting to remote server xxxxxxxxx failed with the following error message : 
WS-Management cannot process the request. 
The operation failed because of an HTTP error. 
The HTTP error (12186) is: The client certificate credentials were not recognized. . For more information, see the about_Remote_Troubleshooting Help topic.'

So, Can anyone help me:

• Identify what I did wrong?
• Understand how to fix these error messages?