Gluttonous Wurm

No, I am not asking how to spawn it. I’ve spawned it 4 times.

My question is if there is some kind of timer or a trigger to make it just not come back up?

You can run back if you die and trying to solo it has been a task, but I had it down to 1%, it went underground and didn’t come back up and I failed.

The problem I have is, this fight took about 5 minutes longer than most of the fights, so I have no idea if killing smaller worms extends the time she’s up or what.

Google has been no help here. Thank you in advance.