When I trade with a villager and unlock the next trades and then break the jobsite, I try to trade with him and it just quickly closes the trade menu.
- Open the provided world
- Notice the villager just in front of you has its GUI immediately closing
Acquiring op on the provided world (open to LAN), running
shows the villager has no working station assigned to him. Then placing any lectern, the villager will take the job station and his trading will be fixed. Note if you remove the lectern you have just placed, the bug with his trading GUI will start over again.