There are a lot of stray lines with perspective on the screen after loading the shader.
Game version: 1.20.4 Fabric*
Shader loader: Iris Shaders

#The content is translated from Chinese and may contain errors

this may be a conflict between iris and some other mod.

can you try removing all mods.
but do not remove the "iris" mod and other mods it needs, like "sodium"

if the problem stops happening without extra mods, it was a conflict between mods

Bleh, the original is fine, but my game has over two hundred mods ! Uploading image.png...

i will not be able to find the problem unless you determine if it is a mod incompatibility or not.