I had a save with Grace route before but I decide to start over due missing some scene with mini-cam and I just done the 2nd playthrough with Izumi (REL) route by yesterday, so I still have no idea how to unlock Izumi's apartment on her FEAR path and Grace's routes
U might have to ask
@SmokeyDots directly for the solution
Before that, did u by any chance cheating on the game? Because as SmokeyDots said, a reckless use of cheat could ended up messing with the game event's timeline
Just saying since I've no idea for solving ur issue if it's happened while u didn't cheating at all
I'm just using the save editor to speed up the stats lvl btw, pretty much carefully so I didn't mess the timeline