Unfortunately when running the primals and dungeons, you have to be pre-emptive rather than the intended reactive because of this crap.

I have noticed however if I run out of an AOE and stop dead and do nothing just outside its border they don't hit. If I run through and keep running I do get hit a lot, its the same as I'm using an ability as I clear the border. Id love someone to test and tell me if its my imagination ?!