Information provided by remote host is not captured when channel session is rejected

I've got an intermittent crash I'd like to track down a bit better:

Unhandled Exception: Renci.SshNet.Common.SshException: Failed to open a channel after 10 attempts.
   at Renci.SshNet.Channels.ChannelSession.Open()
   at Renci.SshNet.ScpClient.Download(String filename, FileInfo fileInfo)
   at AtlasSSH.SSHConnection.CopyRemoteFileLocally(String lx, FileInfo localFile, Action`1 statusUpdate, Func`1 failNow)
   at AtlasWorkFlows.Locations.PlaceLinuxRemote.CopyFromRemoteToLocal(String dsName, String[] files, DirectoryInfo ourpath, Action`1 statusUpdate, Func`1 failNow)
   at AtlasWorkFlows.Locations.PlaceLocalWindowsDisk.CopyFromSCPTarget(IPlace origin, Uri[] uris, Action`1 statusUpdate, Func`1 failNow)

I can see the spot where this error occurs in the source code. But the reasons for the error or failure to open seem to fail. This failure occurs after 15 or 20 connections are opened (and I think closed) to the same machine. And it doesn't always happen.

How can I better track down what is causing this failure?

Start at Renci.SshNet.Channels.ChannelSession.Open() and follow the failure into ScpClient.Download(), using the reported stack trace as the entry point. Reproduce the intermittent rejection after repeated connections and determine what remote-host information is lost; done means the failure exposes enough context to identify its cause.