Why is VIM starting in replace mode?
Solution 1:
I have just identified that the issue only occurs when connecting to the remote system using the native OpenSSH client released with Windows 10 1709 using the ConEmu terminal emulator. If I use the same client with native powershell or cmd there is no difficulty - appears to be an issue with ConEmu. Hopefully this helps someone else.
Solution 2:
Seems to be an issue with utf-8 ambiguous characters and Windows cmd console. Flag t_u7 is set by default and so vim will request cursor position and get a bad reply from the ssh client.
Workaround: Adding set t_u7=
or set ambw=double
to your vimrc should fix the problem. set t_u7=
will disable requesting cursor position and ambw=double
will set the ambiguous characters mode to double.
For more info see vim reference manual: https://vimhelp.org/term.txt.html