Thin Update should also use 21 by default as HPDM does.
Three question here:
1. For both HPDM and Easy Update, are you also set the IP address exactly same as you input in the x-terminal? (I'm asking this to eliminate hostname or FQDN issue)
2. Which FTP server are you using? is there any logs from FTP Server side to indicate the failure?
3. Is there any special characters in user name or password?