Hi. I'm doing the Hard Answers quest line. Now, I've played and beaten this game multiple times, but there's always issues where I get stuck in areas that I previously cleared before. Maybe it's just an absence of memory. Anyways, I do the quest to kill the giant spider, and I get the key from Calcelmo. But the key will only allow me to access the museum, the laboratory is still locked and the only way to access it is to unlock it. Unlocking it a major problem for me, though, because the lock is expert.

I've looked online for guides and it seems to me that people are playing some kind of different version of the game, because the key they get from Calcelmo also unlocks his Laboratory.

I don't know how to get past this. I've been known to be very ignorant with things like this. When I had to poison the batch of brew from the other Thieves Guild questline I kept leaving the caves where I entered them. /stupid

Can someone tip me off as to what I'm doing wrong?

EDIT:

Also, i'm playing Skyrim Special Edition for the Xbox One, with a few mods. The mods shouldn't affect this though.

IIRC, the Museum key is only good for the Calcelmo's museum and not his lab. Check around the personal quarters in the museum and see if you can find another key or maybe pickpocket a guard.

Anyone with CK access (PC user of course) should be able to verify if both doors use the same key. If so, a mod did it, but we won't know if it was intentional.