SshClient - thread gets blocked indefinitely, lock not released

Using version 2020.0.0-beta1 SshClient, I was doing some load testing, and consistently encountered an issue when executing commands for an extended period of time using a single client instance (a few hours running around 1M commands).

When running the SshCommand.Execute() method, the method SemaphoreLight.Wait() waits for a lock to be released indefinitely. (SemaphoreLight.cs : Line 110)

Call stack:
System.Private.CoreLib.dll!System.Threading.Monitor.Wait(object obj, int millisecondsTimeout, bool exitContext)
Renci.SshNet.dll!Renci.SshNet.Common.SemaphoreLight.Wait()
Renci.SshNet.dll!Renci.SshNet.Channels.ChannelSession.SendChannelOpenMessage()
Renci.SshNet.dll!Renci.SshNet.Channels.ChannelSession.Open()
Renci.SshNet.dll!Renci.SshNet.SshCommand.BeginExecute(System.AsyncCallback callback, object state)

As a workaround, disposing and recreating the SshClient object after every 10000 executions solved the problem.

Start with SshCommand.Execute and its BeginExecute call path, then inspect ChannelSession.Open and SemaphoreLight.cs around line 110. Reproduce the long-running load test described in the issue using one SshClient and observe where the wait remains blocked. Done means extended command execution no longer leaves the client waiting indefinitely.