Collections Bug?

I think I discovered a bug in the collections part of the PSX version of FFII.

Initially in Fynn you can only get a few kew items and treasure, with the rest of them mostly undicovered until your party retakes Fynn. I was very systematic and managed to get all but one treasure in the castle and basement. I assume the remaining treasure is a key item I can't access yet. The collections menu duly recorded this fact.

After defeating the Barrel Worm in front of the tower I went back to discover the collection menu for Fynn reverted to it's pre-liberation state. I've gone back and double checked to see the chests were indeed opened. Some of the items are in my inventory still.

I'm not sure if the percentage was affected. I don't mind the reporting being off if I can still get 100%.

EDIT: Nevermind, I was misreading Fynn as Fynn Castle. I didn't realise they didn't count as the same place.