I have installed and run Way of the Hunter using both Proton GE 10.5 and using Proton Hotfix with Steam.
When the application starts it asks what to run it under (run, DirectX11, DirectX12) and I chose the first option. (no explanation what that selects for video)
Cache construction happens as normal.
Application starts, music plays, but screen is black.
Clicking around I someone ended up in my saved game.
Screen is still black.
I ALT-TAB out of the application and the screen comes up visible!
If I move the mouse back into the application it goes black.
This application has always been a platinum for Proton. This is a Wayland/NVidia issue I believe.
System: