I see that WinSCP checks if FTP is available when SFTP fails. Can WinSCP be configured to never try FTP, do not look/check/try/knock, only use SFTP. If SFTP fails, game over. Do not try anything else for any reason.
Failed to connect to aaa.bbb.ccc.ddd: Network error: Connection timed out
Knocking FTP port.
FTP port opened, will suggest using FTP protocol.
Script: Network error: Connection to "example.com" timed out.
The server rejected SFTP connection, but it listens for FTP connections.
Did you want to use FTP protocol instead of SFTP? Prefer using encryption.