Thank you for posting your feedback; my apologies on the delay for my response.
You are right! There is a weird bug with the auto-save, even if you disable it in the options menu. I'll take a look into it. I will also swap the auto-save slot from slot 1 as I am getting several bug reports regarding it. This is a bad one, and I'm sorry for the trouble it has caused you.
I am also fixing the Rand blocking the door bug in the Arena, as well as warp areas in the Eva houses.
There appears to be a bug where the buff is not applying to new party members for Light Exp boost. Fixing it now.
Modifying how Petrify works to prevent soft-locks.
Again, I greatly appreciate you taking the time to play the game and report the bugs and feedback!