For PI-CHO to look correct, you typically need a weather mod like Cathedral Weathers or NAT.ENB . Installation Guide

It includes customized post-processing shaders, support for various weather mods like Cathedral Weathers, and multiple quality presets (from performance-friendly to ultra-high quality).

Installing PI-CHO requires placing files directly into your Skyrim Special Edition root directory (where the game's .exe file is located).

This is often caused by an incorrect installation of the weather mod or a conflict with a "Reshade" preset.