Problem: When you try to change the scaling option, it always reverts back to to default option, which is - "Use my display's built-in scaling"
In order to enable scaling, here is what you need to do:
1. Go to change resolution
2. Select a non native resolution and enable it
3. Now, go back to the scaling option and select "No scaling" and enable it.
Once you do this, the option should be available for all resolutions. I tested this on multiple monitors all using Nvidia video cards using the latest drivers - 258.96.