Same thing happening with me. Getting very annoying now. It seems to happen to me when I change characters while in Protector's Enclave. Once I've changed back to the original character this starts happening. Then I can't log any character in to PE.
Also had flickering in Helms Hold. It only happened where the reddish fog transitioned from the clear areas. Once completely into a "red fog" area the flickering stopped.
My plans will be to explore and work on the quests as much as possible. I'm an explorer at heart and finding those little known places gives me a sense of accomplishment.