Hello,
I am running Kubuntu 22.04 on this PC for a while.
It has a nVidia GTX 650 2 GB.
A while ago, there was a kernel update and now, the nVidia drivers don’t work.

Info Center says that the driver is llvpipe or something like that.

In System Settings -> Driver Manager
Additional Drivers
The 470 nVidia driver is selected but the Apply Changes and Revert buttons are grayed out.

Did some file become corrupt?
Normally, don’t buttons are always enabled.
There is no error message.

I do not use this distro nor I use nVidia legacy proprietary drivers. I'm just guessing your Kubuntu is loading nouveau by default and your GUI tool is not intended to install older versions of proprietary driver. If you still want the blob you have to do it manually from CLI, methinks.

Apparently, it is using the nVidia drivers but it is a fallback when we see llvmpipe. The performance is obviously lower.
This problem started some months ago when there was a kernel update and suddenly, there were a bunch of kernels installed on the system.
One was called 6.1..something..oem
6.1..something..generic
6.1..something..oracle

Right now, I made it use 5.15.0-83-generic but the nvidia driver has some problem.
When I tried to install nvidia's official driver manually, it said something about the kernel being maybe compiled with another version of cc and maybe it would fail and then it failed to install.

Sounds like some joker at Canonical made some major changes and caused breakage.

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