FTP failing: 200 PORT command successful. Consider using PASV. 425 Failed to establish connection

[bobmeetin]

I use common linux/unix command line ftp to ftp files to/from my vesta host from my Linuxmint desktop. This has worked for many years, at least up until a couple weeks ago. Without accessing VestaCP or making any system changes via SSH it just started failing:

~/Desktop$ ftp server_name.xyz
Connected to server_name.xyz.
220 (vsFTPd 3.0.2)
Name (server_name.xyz:local_user): user_account
331 Please specify the password.
Password:
230 Login successful.
Remote system type is UNIX.
Using binary mode to transfer files.
ftp> send templates+themes.txt
local: templates+themes.txt remote: templates+themes.txt
200 PORT command successful. Consider using PASV.
425 Failed to establish connection.
ftp>

SSH works fine. I substituted the server name and user account names to hide them. With the correct account info I apparently get logged in but when I attend to send or put a file get the response above.

200 PORT command successful. Consider using PASV.
425 Failed to establish connection.

Can you point me to what needs to be modified either via VestaCP or command line SSH (including folder) so that we can get it working again? I'm scratching my head wondering why it suddenly broke with no administration changes.