Blackrock mountain ,summoners tomb

I was trying to finish the dungeon of Blackrock mountain yesterday spending 2 hours to actuly get the same bug twice in row even after i reseted the entire dungeon twice, after i i start the boss fight on the summoners tomb , i end up on a bug wwhere the seventh boss doesnt take agro , blocking me both doors and not letting me to continue the dungeon.

This happened to me even before when i was low lvl with a group but i thought it was just a simple bug so we just pass it behind , today i wanted to get the achivment and explore this dung , and i cant , i was wondering if you could actuly do something about it , thank you for your time reading this .

My Acc name is Tsmchaseme , char Egirllover, realm lordaeron.