Internet protocol version in script

Hi
All of a sudden I can't login to my site without forcing WinSCP to use IPv4 in the connection settings.
Two questions:
How do I do this in a script? All of a sudden my script don't work no more.
The Auto setting is now greyed out, I can only set IPv4 and IPv6, is this a bug?

I upgraded, seems to have fixed the login.
Auto is still greyed out..

I was too early, the script still won't login. :(

The Auto setting is available with SFTP protocol only:
https://winscp.net/eng/docs/ui_login_connection#ipv

In script, use AddressFamily raw session settings:
https://winscp.net/eng/docs/rawsettings#addressfamily

-rawsettings AddressFamily=1 works, thanks.