Bug on buying Pharmacy Books in Vatican?

[MikePrime13]

I think I may have encountered a bug -- I've collected 13 out of the 15 medicines so far, and I have unlocked Moxie 1. But right now when I go back to Valeria, the game keeps telling me that the books are locked and cannot be bought until I speak with Valeria.

I've cleared Nun in trouble and the long-ass catacombs quest, so I think I've progressed in the game further enough.

Is this a bug, or this is a lock that I cannot unlock more books until I progress further in the game?