Minecraft 1.12 Pre-Release 2
- Create new world
- Kill Ender Dragon
- Teleport through End Gateway
- Drink Speed potion or type /effect @p speed 100 100 (should give Speed 100)
The potion won't take effect until the player relogs.
MC-92916 Player is removed from the EntityTracker when teleporting to unloaded chunks or changing dimensions, resulting in client side desync