I just recently passed this level, and I had many weirdness/issues:

1. Why is the starting point is different? You can see a playthrough here https://youtu.be/MwIRklbNcMU where we start closer to the collectible item there.

2. From when I started the level and after I finished it, the chapter select stays locked. Chapter 7's there, 9's there, but 8 isn't. Is this intentional?

3. I got stuck at a blackscreen after finishing the level, after the dialogue. Next level didn't load. Verifying seems to fix it though.

4. Not sure if it's a bug or intentional (due to the level's name) but if we take an alternate route, not going thru the main cave entrance, a spidercrab blocks our way, and it won't move away.