I apologise if this conclusion is already understood, but I suspect it’s here your issue stems from. That seems to be echoed by Resolve’s error message.
Firstly, if you have an option in the BIOS for it, make the Nvidia the primary GPU.
Then perhaps you might get some direction from here on how to expressly use that GPU.
https://wiki.archlinux.org/title/NVIDIA_Optimus#Use_NVIDIA_graphics_only