Setting a Trap Quest

I went to the stone to summon kross the trex. The mob appeared then despawn and it used my ritual stones.Now they are gone and I didnt even get to fight the mob

Same thing happened to me last night… I went to summon Kros, then all the mobs spawned in and kros pretty much one shot me. I died. stones are gone. That’s about as much it takes for me to be done with the remix MOP. If i wanted to play Classic for a tough experience I would but come on Blizzard.,

“I went to summon Kros, then all the mobs spawned in and kros pretty much one shot me. I died. stones are gone.”

For me the quest says “Suggested Players [5]” so I don’t think that’s a bug.