I don't know if it's related to the domain records pointing rules.
I configured for other website as well and they are fine. I used 8080 as the port for the websites. But for this particular site, every time I input the domain:8080 in the address bar, it automatically cut off the :8080 and leave it only the domain part xxx.com. ( cut off www. at the begin part as well).
Anyone has clue where to look into? Thanks!