The two librarians that spawn in this village will offer trades of other professions. If you make a trade with them and they gain new trades, the new ones are correct. What profession the wrong trades are from seems to be random and is different when recreating the world. Other librarians in other villages offer correct trades, as do librarians spawned by an egg.

I recreated the world using the same seed, and the same two librarians have the same issue.

Seed: 1279011524366905913
Coords: -943 65 720