Comment 1 for bug 1860367

=== Nvidia Quadro P620 Graphics Card ===

Similar problem occurred for my desktop using a Nvidia Quadro P620 Graphics Card.

My newly updated Linux is:
   $ uname -a
   Linux host1 5.3.0-26-generic #28~18.04.1-Ubuntu SMP Wed Dec 18 16:40:14 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux

My prior Linux was 5.0.0-36 (graphics and multi-monitor support worked fine here).

==== Symptoms ====

After an update to latest Linux, 5.3.0-26-generic, monitor support had reverted to a single monitor at low resolution. The graphics responsiveness was very slow, but usable.

No monitors were not recognized.

1. Open the "Displays" dialog
2. Only *one* monitor is detected (though four monitors are connected)
   The one monitor is listed as "Unknown".
3. Previous to the Ubuntu update, multiple monitors were recognized.

==== Fix ====

I "fixed" this by selecting a new driver:

1. From "Software & Updates"
2. Select tab "Additional Drivers"
3. Select the latest nvidia driver (I selected "nvidia-driver-435 (proprietary, tested)".
4. Click "Apply Changes" (this takes a minute to complete)
5. Reboot.

=== Nvidia Quadro 600 Graphics Card ===

Same occurred for a colleague using a Nvidia Quadro 600 Graphics Card. The colleague updated to the latest Linux. After reboot, the graphics were very slow and only displayed on one monitor.

The "broken" Linux version for the colleague is:
    $ uname -a
    Linux host2 5.3.0-26-generic #28~18.04.1-Ubuntu SMP Wed Dec 18 16:40:14 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux

However, different than the previous case above, the Quadro 600 driver support stops at nvidia-390.
The colleague had to select the old driver "nvidia-340".
The colleague tried returning to the "nvidia-390" driver, but the same problems occurred (no multi-monitor support).