Post updated 2020-11-04: To reflect that latest nvidia packages are in non-free/updates repository rather than non-free/testing.
Thanks for reporting @HighKing.
This repository contains the latest nvidia packages. Note there is no cuda package, any cuda package you find is something leftover from the past. There are no plans to develop any cuda packages or anything beyond what is in the testing repo. I will be moving the packages in the testing repo to non-free/updates repo.
If you aren’t getting the latest packages when you do transactions that would mean your package metadata is out of date and/or there are still some older packages version in cache. To clean this up run:
$ sudo dnf clean all
Then run the command to install the nvidia proprietary driver. I will modify the commands in first post so other users avoid this issue.
Today you should end up with nvidia-440-440.64-4 if it is nvidia-440 that you are installing.