Problem:

Clicking an enchanted book trade moves the emeralds to the trade area, but not the enchanted book.

Additionally, when the villager has two emerald trades at the same level, and one is an enchanted book and the other is not, clicking the enchanted book trade causes the UI to behave as though you had chosen the other trade.

Additional Info:

This happened in a survival server, and again in a new creative singleplayer world when I went to test if it was a connection issue. I restarted my game and the same bug occurred.

So far it doesn't seem to happen to any other trades.

Screencaps: