Can't choose GPU when multiple GPUs exist

[CodenameCookie]

Seems this method to choose AMD or Nvidia does nothing anymore. By changing gpu-preferences.json in this directory: C:\Users\Username.cache\lm-studio\gpu-preferences.json
It didn't exist and creating it with "amd" did nothing. So either that seems to have changed or it never worked.

{ "gpuType": "amd", "modelFileFormat": "gguf" }

Why are you making it so hard to use your software? Surely this is basic functionality?
I know it's free but you're not making using it very attractive.