Unfortunately I'm about out of ideas.
You could try renaming your [server]_[character]_eq2_uisettings.ini to something else and then restarting your client to see if the issue is a corrupted UI file. If you don't want to do this, try making a new character who will have a fresh uisettings file.
I don't think this would matter, but you could also try renaming your eq2_recent.ini file before starting your client.
Are the stats updating properly? You can test this by typing /dynamicdata general.ping and it should show the current ping value in the chat window.
You didn't mention this specifically, but did the eq2ui_mainhud_connectionstat.xml file exist in your UI/Default directory? Open this file with notepad, does it have text in it?
LINK
(Rothgar) Re:connectionstats window..
