Hey, appreciate the advice. I just would like to note that it seems intentionally blocked so you can do the nun walk, revive Blake, then come back. 
How to do that: go into the casino, talk to the owner of the place, get nun outfits, and walk right in. That should fix the switch issue.

Hey professor Hep, I'm guessing you were meaning to reply to Sunflower. If so, then you may have forgotten to click on the reply button on his thread. Thought I'd let you know for the future.

It's quite a well known bug in here. This is strangely the only area that does this, and I'm guessing they forgot to change a bit of the code to reference the rpgmvo file that is the exact same.
There are two fixes to it: a temp solution and a tested solution that is reliable (until the next update that is.)

Reliable solution:
To fix it, find in the audio folder bgm, and  find two files that state "El Infausto Landron de Joyas A.rpgmvo" and "El Infausto Landron de Joyas B.rpgmvo"
You'll want to copy them (just in case of corruption) and change the names respectively to "El Infausto Landron de Joyas A.ogg" and "El Infausto Landron de Joyas B.ogg"

Temp Solution:
You can do what I did first time playing it, which was spam the enter key until I got to the underground section, save the game, and refreshed the game. That also seemed to work as a fix.