I'm testing your demo trial of the .Net SFTP library for CF 2.0 (RebexSftp-2016R1.1)
The sample runs fine, and i can log in a SFTP server, upload/download files, etc... but all the time that i disconnect the client i get an entry on the log server: 'An existing connection was forcibly closed by the remote host'.
I'm using your Rebex tiny SFTP server, but i already tried with other servers and the behaviour is the same.
Using another SFTP client (for instance FileZilla) i don't get the warning entry on the server and i get a graceful disconnect.