From what i understand this is an issue with NVIDIA gfx. I had the same issue with just playing on steam and got it to work with launch option listed below, BUT when trying to play through plutonium I have tried several different versions of proton and used this luanch option and still get black screen with audio. Not sure the fix but maybe someone smarter will be able to link whats wrong.

VK_LOADER_DRIVERS_SELECT="nvidia" DXVK_FRAME_RATE=120 DXVK_ASYNC=1 PROTON_USE_NTSYNC=1 PROTON_NO_FSYNC=1 PROTON_NO_ESYNC=1 %command%