Craglorn: The Missing Guardian -- What am I missing?

Shagreth

So, the first boss in there takes like 10.000 auto attacks to be defeated, then you proceed to the next one only to find out that it's bugged (the snake never comes down after breaking the orbs) I waited 1 hour for the dungeon to reset, then got tired of auto attacking the first boss and logged out. Any suggestions welcome, there has to be some kind of trick. What a buggy mess and I see that it has been this way for years.

Ramei

It wont spawn enough lamias to activate the stones three times so the serpent never moves. Tried it twice. First ttime the serpent actually vanihed altogether and I had to abandon the quest and start over. Second time serpent stayed but didn't send enough lamia's to finish the stones.,