Comment 10 for bug 1866377

Richard's magic work-around WFM:

apt purge --reinstall plymouth
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following package was automatically installed and is no longer required:
  libplymouth5
Use 'apt autoremove' to remove it.
The following packages will be REMOVED
  lightdm* plymouth* plymouth-label* plymouth-theme-spinner* plymouth-theme-ubuntu-mate-logo* plymouth-theme-ubuntu-mate-text* plymouth-theme-ubuntu-text* slick-greeter*
0 to upgrade, 0 to newly install, 8 to remove and 0 not to upgrade.
1 not fully installed or removed.
[...]
Processing triggers for systemd (244.3-1ubuntu1) ...
Processing triggers for dbus (1.12.16-2ubuntu2) ...
Processing triggers for initramfs-tools (0.136ubuntu1) ...
update-initramfs: Generating /boot/initrd.img-5.4.0-14-generic

apt autoremove
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages will be REMOVED
  libplymouth5
0 to upgrade, 0 to newly install, 1 to remove and 0 not to upgrade.
After this operation, 425 kB disk space will be freed.
Do you want to continue? [Y/n]
(Reading database ... 503753 files and directories currently installed.)
Removing libplymouth5:amd64 (0.9.4git20200109-0ubuntu6) ...
Processing triggers for libc-bin (2.30-0ubuntu3) ...