RPCClient hung on close

[jyrijh]

https://github.com/rabbitmq/rabbitmq-tutorials/tree/master/dotnet-6/RPCClient

Tried the RPC tutorial and client never closed for some reason.
I got the result back from server and showed it and then it got hung on connection.Close().
I added these and then it run to end

public void Close()
    {
        if (channel is not null && channel.IsOpen)
            channel.Close();

        if (connection is not null && connection.IsOpen)
            connection.Close();
    }