Game freezes at certain areas and client is not responding

Some areas lag like vailance keep for alliance , i was exping my warlock just a few mins ago and client stops responding in dragonblight. at bottom right where u have to kill some soldiers and pick up some armors for the quest. game is running smooth all the time for me but at certain areas it needs to be fixed
I had to relog 10 times and now i have to use unstuck cause it stucks in loading screen. to be more specific the freeze happens at new hearthglen in dragonblight

it happened to me at hearthglen

I would create a new topic about it and found this one. It happened to me 3 times at New Hearthglen in Dragon Blight and i could not log in other characters in account as well. It kept telling "login failed" till i use unstuck option from website. This area definately has a bug