Comment 28 for bug 1771185

I got it fixed after upgrading from 18.04 to 19.04, but it was not upgrading that solved it. The issue is still there in 19.04.

The solution for me was disabling secure boot, purging the nvidia drivers and then reïnstalling them.

Apparently when secure boot is on, the nvidia-drivers do get installed, (and they show as in use by the GUI provided for it in Ubuntu) but do not get loaded. I figured this out when running nvidia-settings from terminal. It showed an error: nvidia not loaded.

In other words, if a developer is watching this, there are two bugs:
- 'not loading of the nvidia drivers' when secure boot is on.
- The hardware drivers GUI in 'software and updates', shows the proprietary driver is in use, while it is not, it's only installed, but not running.

I hope this helps.