Larian Studios Forums Divinity: Original Sin 2 Divinity - Original Sin 2 - General Beast Quest bugged? (Magister's key)

Beast Questline:
My journal is currently stuck where it says: "Beast stumbled upon a childhood friend in the Fort Joy Arena by the name of Carson. He gave us a key that unlocks one of the prison's doors. Now, we just need to figure out which one." (its called "Magister's Key")

After some research, I found out which door its supposed to open to advance your journal: It's the door you need to use the teleport gloves to get up to the second level to drop the ladder down for your party. It's in fort Joy to the east of Camp Kitchen, just to the right of the big guarded gate with Magister Borris, behind Mona's big tent (the diseased woman who sells necromancy skillbooks).

The problem is, I picked the lock earlier in the game - the door Beast's key was supposed to open to advance the journal. Nothing on google helps, IGN's Beast quest guide is blank, the wikis aren't a help either.

I can confirm this door being unlocked specifically by Beast with the specific key given to him by his dwarf acquaintance Carson after winning in the arena will advance the quest in your journal, but that was way too long ago to go back.

If anyone can confirm they've been able to advance Beast's quest line if they didn't have him use the correct key on this specified door, please let us know!