The item cooldowns are rendered in front of item tooltips. This was probably caused by it having a texture file now.
This is not an issue in 1.21.1 so it seems it was introduced in the 1.21.2 snapshot cycle.
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Steps to Reproduce:
Use the following command to give yourself ender pearls
/give @p minecraft:ender_pearl[minecraft:use_cooldown={seconds:255},minecraft:max_stack_size=99] 99
Use an ender pearl
Arrange them in your inventory so that they are under where an item tooltip is.
❌ The item cooldown renders in front of the item tooltip
Can confirm.