[Bug] Act 1 boss battle glitch, falling out of map bounds

Right after going onto the elevator at the end of Act 1, the level and boss animation fail to load, sending the player character plummeting down towards a dead end area with no assets.

This occurred on Switch, before and after patch 1.1 was installed. It is still an active bug today. Gameplay progression is blocked by this.

Deleting the game's local files and reinstalling did not fix the bug.

Video: https://youtu.be/8aUS6aKJUAo?