Does your WoW ever disconnect but you can immediately log back in?

So this is a unique kind of DC. What happens is my WoW will freeze, like the kind that's usually followed by a DC but it never happens, it just stays frozen. I can open another client though and log back in (even be in the same BG/dungeon). Now after I log in with this new client, the frozen one will close by itself.

I was thinking if it was an addon issue so I've been disabling them but it still happens. Strangely I've had the same set of addons for almost half a year without issue but this has only been happening for the past month. How can I find out the specific cause?