Comment 12 for bug 1880564

1:0.8.4~0.20.04.2 solves the problem, and LP: #1875339 is definitely fixed too:

:~$ apt-cache policy ubuntu-drivers-common
ubuntu-drivers-common:
  Installed: 1:0.8.4~0.20.04.2
  Candidate: 1:0.8.4~0.20.04.2
  Version table:
 *** 1:0.8.4~0.20.04.2 400
        400 http://archive.ubuntu.com/ubuntu focal-proposed/main amd64 Packages
        100 /var/lib/dpkg/status
     1:0.8.1.1 500
        500 http://it.archive.ubuntu.com/ubuntu focal-updates/main amd64 Packages
     1:0.8.1 500
        500 http://it.archive.ubuntu.com/ubuntu focal/main amd64 Packages
     1:0.8.1~ppa3 500
        500 http://ppa.launchpad.net/albertomilone/u-d-c-release/ubuntu focal/main amd64 Packages

:~$ apt-cache policy dpkg-dev
dpkg-dev:
  Installed: (none)
  Candidate: 1.19.7ubuntu3
  Version table:
     1.19.7ubuntu3 500
        500 http://it.archive.ubuntu.com/ubuntu focal/main amd64 Packages
        500 http://it.archive.ubuntu.com/ubuntu focal/main i386 Packages
        100 /var/lib/dpkg/status

:~$ prime-select query
nvidia

:~$ nvidia-smi
Mon Jul 27 18:16:39 2020
+-----------------------------------------------------------------------------+
| NVIDIA-SMI 440.95.01 Driver Version: 440.95.01 CUDA Version: 10.2 |
|-------------------------------+----------------------+----------------------+
| GPU Name Persistence-M| Bus-Id Disp.A | Volatile Uncorr. ECC |
| Fan Temp Perf Pwr:Usage/Cap| Memory-Usage | GPU-Util Compute M. |
|===============================+======================+======================|
| 0 GeForce RTX 2060 Off | 00000000:01:00.0 Off | N/A |
| N/A 44C P8 3W / N/A | 452MiB / 5934MiB | 0% Default |
+-------------------------------+----------------------+----------------------+

+-----------------------------------------------------------------------------+
| Processes: GPU Memory |
| GPU PID Type Process name Usage |
|=============================================================================|
| 0 1107 G /usr/lib/xorg/Xorg 134MiB |
| 0 1656 G /usr/lib/xorg/Xorg 135MiB |
| 0 1906 G /usr/bin/gnome-shell 165MiB |
+-----------------------------------------------------------------------------+