Proprietary nvidia driver isn't supported by kernel 5.9, you'll have to wait mid-november for nvidia to make it usable.
https://forums.developer.nvidia.com/t/nvidia-driver-not-yet-supported-for-linux-kernel-5-9/157263
@nikolal
I believe Linus Torvalds had something to say about things like this:
https://www.youtube.com/watch?v=_36yNWw_07g&t=13
