All enchanted books show up as "Protection" in 18w22b, 18w22c

I created a game in 18w20a, and then incrementally upgraded it to 18w21b without apparent issues.

Then, when upgrading the game to 18w22b, and when upgrading it to 18w22c, all preexisting enchantments on books will either start showing up as, or will be converted into one of the levels of the "Protection" enchantment.