The Abbot's List quest help plz

Ok so how am I supposed to open the second door in the abbot’s room? I unlocked the first door that connects to the library with the prior’s keys but they dont unlock the second door and it requires a huge lockpicking skill (it’s very hard atm). I also have the monastery keys that you pick up in the pantry but they don’t work here. To understand better which door I’m refferring to it’s the one at 4:04. The prior seems to open this door everyday in his duties so his keys should do the trick but no…