Class/Level: Monk, lvl 35+

Steps:
1. Encounter any form of knockback
2. Cancel the knockback by Thunderclapping to a target

This has been witnessed by many users across a variety of specs, both when they, or someone else is affected by the bug. It's purely graphical, as everything seems to function as per usual, and attacking does not seem to 'cancel' the invisibility.

Short video showing bug: https://streamable.com/tckee2