Endless Collapsing Vault in Grushnak

[Fwiffo]

For some reason, the Grushnak collapsing vault in the green goo became endless (at least I think so, quit after 50 floors), and later floors dropped t3 loot instead of t4-t5, with enemies going down in level to 17 at the lowest from what I've seen.
If I read the book inside that vault, I also get teleported to the floor with the original vault entrance.

Full save:
https://drive.google.com/file/d/1gHxgKj ... sp=sharing