Vulkan cannot use dedicated radeon graphics card

[Yochanan]

DX11 issues starting Proton games

The radeon driver does not support Vulkan, only amdgpu does. You can try installing amdgpu-experimental and reboot. If it works, you’ll boot successfully and running inxi -Gazy will report the driver as amdgpu. If it doesn’t work, you will not boot successfully. If that happens, switch to a TTY, remove amdgpu-experimental and reboot.