I believe you're supposed to max out the barghest before the underground segment, and then afterwards interact with the rubble blocking the switch.
No idea why there would be a glitch like that, but that definitely isn't intended... Sorry that I can't help you with it, my man.
Akane is obtained via going out the back door within the temple, inspecting the sparkle, then using what you get from there on the wall. That should give you a memento, which you need to use in the next chapter. After going through it, chapter select back to the chapter you were on and you should automatically obtain her after a short fight.