Local Media CommunicationsClient hangs on exit

Describe the issue
An application with a local media CommuncationsClient hangs on exit and never terminates.
Only if forcing exit with Environment.Exit() enables application termination.

The CommuncationsClient in application does nothing except initialization and termination.

Problem can be reproduced in the minimal application below.

I'm using the latest Microsoft.Graph.Communications.Calls.* packages version 1.2.0.791.

Code Snippet
`
graphlogger.txt
static void Main(string[] args)
{
var logger = new GraphLogger(name);

        var builder = new CommunicationsClientBuilder(name, appId, logger);

        var authProvider = new AuthenticationProvider(name, appId, appSecret, logger);

        builder.SetAuthenticationProvider(authProvider);

        IPAddress publicIpAddress = Dns.GetHostEntry(serviceFqdn).AddressList[0];

        builder.SetNotificationUrl(new Uri("https://dummy-notifurl"));

        builder.SetServiceBaseUrl(new Uri("https://dummy-serviceurl"));

        builder.SetMediaPlatformSettings(
            new MediaPlatformSettings
            {
                ApplicationId = appId,
                HostingEnvironmentConfiguration = HostingEnvironmentConfiguration.Default,
                MediaPlatformInstanceSettings = 
                    new MediaPlatformInstanceSettings
                    {
                        CertificateThumbprint = cert,
                        ServiceFqdn = serviceFqdn,
                        InstancePublicPort = publicPort,
                        InstanceInternalPort = internalPort,
                        InstancePublicIPAddress = publicIpAddress,
                    },
            });

        var client = builder.Build();

        client.TerminateAsync().Wait();
        client.Dispose();

        // Uncomment line below to enable application exit
        // Environment.Exit(0);
    }

`

Expected behavior
Successful termination

Graph SDK (please complete the following information):
1.2.0.791.

Call ID
Provide the list call ids that encountered this issue. Include the time in UTC/GMT when these call have occurred.

Logs
See attached.

Additional context
Add any other context about the problem here.

Start with the minimal application shown in the issue and reproduce the hang around client.TerminateAsync().Wait() and client.Dispose(). Review the attached graphlogger.txt for shutdown activity. Done means the application terminates successfully without requiring Environment.Exit(0).