It seems that Net::SFTP::Foreign is requesting to use just password authentication.
in reply to Re^4: Does Net::SFTP::Foreign support identity file and user password?
in thread Does Net::SFTP::Foreign support identity file and user password?
Could you activate debug mode to see exactly how it is calling ssh?
$Net::SFTP::Foreign::debug = ~(8|16|1024|2048);
Show me also your script code.
When I try it myself ssh gets the right preferred authentications list:
May you be clobering the more argument passing a second one with the '-vvv flags?
debug3: preferred publickeys,password,keyboard-interactive