Enchanted Books found in chests or fished don't have enchants.

Seed for testing: -1469366519271110166

There's a temple right near the spawn point containing an enchanted book. It has the enchanted glint effect, but no enchantments.

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Found in a Stronghold chest in one of the wood 2-level areas with the well in the middle and the ladder to get to the second level.
Has no enchantments, enchantments do not appear when combined with another enchanted book.
Seed: -272317511993219009
XYZ: -79 / 24 / -852

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New world generated with snapshot (world seed -7582695434467690280, default conditions). Found an enchanted book in a chest in the jungle temple near to spawn, and the tool-tip shows it as an "Enchanted book" in white, without the specific enchantment.