Thanks Colin. I'm not running a Double Nat and I will restart the router once my wife has finished her uploads. Just out of curiosity where are the WAN SFTP settings you're mentioning? All I see is an option to enable TLS in the new GUI interface as per below. Thanks so much for any help@atkinsom Looking back at @errorsys' previous post I think his issue is with SFTP, not FTPS.
Do you have a double NAT setup?
EDIT: Also reboot your router after making changes to the SFTP settings. I found that when I enabled WAN SFTP access the router didn't update the running vsftpd.conf file and my client couldn't connect. Restarting sorted that out.