Any type of built-in shader will reset when you go into F5 mode.
It doesn't matter what world you're in
It resets no matter what shader you are using
It doesn't matter what resourcepack you are using
How to recreate:
Go into any random world
Enable any shader (Super secret settings)
Hit F5
If you hit F3, notice that the line where it says the shaders are enabled dissapears, meaning it reset.
Linked issues
Comments 1

Duplicate of MC-46727