Lower Guk disappearing mobs
 

Theres a bug in Lower Guk causing some heartache. Mobs will disappear (I speculate that they path out of the playable area or otherwise fall through the floor). They will then reappear in the frenzy room (presumably they run there because that's where they can get up from being under the world). They then path through the dungeon from frenzy to you, picking up a train along the way. This happens quite a lot, and causes lots of trains and lots of groups to need res.

Need specifics on exactly where the puller was standing and exactly where the mobs disappeared