The bug
When the game is paused (normally or using F3+esc), any cooldowns on items such as ender pearls and chorus fruits will stutter visually.
Linked issues
is duplicated by 1
Attachments
Comments 10
Can confirm in 21w03a.
Can confirm in 21w06a.

Affects 21w08b, also affect the chorus fruit.
Can confirm in 1.17.1.
Can confirm in 1.18.1. This doesn't happen all of the time.
Can confirm in 1.18.2.

Although I'm not a developer, I did get this to work with ender pearls on 1.19.2 quite frequently. Might want to have a look at that, devs. 😞
I could not reproduce this anymore in 24w33a. Can you still get the same described result? If so, please update the report with a video showing it.
Can confirm in 20w51a, however, this may take a few attempts to reproduce.