This seems to be a permission issue -- and I am getting the same behavior from the command line ftp program. When I try to put files, even to my home directory, even when 'chmod 0777 .' I get permission denied. I even tried with a windows client. Same thing.
Is it possible the ftp server is configured to prevent uploads? I've tried 'passive off' and 'epsv4' as well.
I can use command-line sftp to upload, but have not been able to login via Net::SFTP.