It is reproducible on RTX 3070. Seems to be a draw call with tessellation and 12 control points. No obvious reason this fails based on looking at the shader diffs though ...
It works fine on RADV. I'll declare this a driver bug. Not exactly super high priority to look into since it's an optional backend, not our bug, and just a goofy glitch.
Seems like Nvidia fixed this. Closing.
Nothing extracted yet.
Summary
There is a graphical glitch in the 3rd chapter of episode 4.
How the glitch looks like:

How it's supposed to look like:

Steps to reproduce
Get my save files from https://drive.google.com/drive/folders/1b4vRPyTu_lJNZh3R7rMYhr2Sl-Uk4Erf?usp=sharing
and put them into: ./steamapps/compatdata/936790/pfx/drive_c/users/steamuser/Documents/My Games/LifeIsStrange3/Steam/<your_steamID>/
Start the game in DX12 mode then do these steps from the main menu:
System info
Proton Version used: 6.21-GE-2