The bug

Thrown tridents that are enchanted will not display the enchantment glint after the world is exited and reloaded. The glint begins to display again if you pick up the trident and throw it again.

To reproduce

Throw an trident with unbreaking 1.

/give @p trident{Enchantments:[{id:"minecraft:unbreaking",lvl:1s}]}

Quit and reenter the save and then the glint disappears.

(Of course, the enchantment will "be back" if we pick it up.)