Kubuntu 20.04 Software Sources; Additional Drivers options greyed out

I just installed Kubuntu 20.04 and I have an Nvidia GTX 1050TI. Now I installed Ubuntu Studio 20.04 a year ago, and I was able to use the "Software Sources" application to install proprietary drivers for my graphics card without any issues.

But now that I just switched Kubuntu 20.04 (Same computer, Fresh Install, No files from Ubuntu Studio's home folder were preserved), All the options in the Additional Drivers section of Software Sources are greyed out, and the only selected option is "Continue using a manually installed driver". Which is weird, since I didn't manually install any drivers.

How do I use a proprietary driver now (Like nvidia-390)?

Will try to attach screenshots later.

UPDATE: Here's a screenshot of the Driver Manager...

https://i.stack.imgur.com/TnQum.png

Solution 1:

Had the same problem, my case solution:

sudo apt purge nvidia-*

sudo apt autoremove

sudo apt install xserver-xorg-video-nouveau