For anyone having issues where Maria is stuck at Level 30, here's how you fix it:
1) Locate your game's save file. (.../game/saves/PAGE-SLOT-LT1.save)
2) Upload it to https://saveeditor.online/.
3) Find the line 'nia_alert00'. Should be stuck at 1.
4) Set value to 0.
5) Download your fixed save.
6) Place the fixed save back in your game's save file folder.
7) Play the game - assuming you meet the requirements, the next scene should be trigger-able as usual. (Starts with Maria and Hana entering your room in the morning.)
I've confirmed this works for me so hopefully it helps someone else, too!
