Hello Chen,
Answers to the questions are below
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) -- Yes,the communication is been done based on IP address only.
2. Which FTP server are you using? is there any logs from FTP Server side to indicate the failure? -- We are using Microsoft FTP Server,I'll try to get you the logs from FTP server.but i don't think there is any failure reported.
3. Is there any special characters in user name or password? -- There is no special characters used in either username or password and is in only lower case.
Thanks