Troubleshooting steps
https://github.com/PowerShell/Win32-OpenSSH/wiki/Troubleshooting-Steps

Terminal issue? please go through wiki
https://github.com/PowerShell/Win32-OpenSSH/wiki/TTY-PTY-support-in-Windows-OpenSSH

Please answer the following

"OpenSSH for Windows" version
((Get-Item (Get-Command sshd).Source).VersionInfo.FileVersion)

Server OperatingSystem
((Get-ItemProperty "HKLM:\SOFTWARE\Microsoft\Windows nt\CurrentVersion\" -Name ProductName).ProductName)

Client OperatingSystem
Win10

What is failing
Sometimes SSH get hung when connecting to Ubuntu 16.04 64bit.
ssh -V
OpenSSH_for_Windows_7.6p1, LibreSSL 2.6.4

I got the debug trace with -vvv:
ssh.txt

Expected output
don't hang

Actual output
hang