$ apt-cache policy plasma-discover plasma-discover: Installed: (none) Candidate: 5.19.5-0xneon+20.04+focal+build10 Version table: 5.20.0-0xneon+20.04+focal+build11 500 500 http://archive.neon.kde.org/user focal/main amd64 Packages 5.19.5-0xneon+20.04+focal+build10 1100 500 http://archive.neon.kde.org/user focal/main amd64 Packages 100 /var/lib/dpkg/status 5.19.5-0xneon+20.04+focal+build9 1100 500 http://archive.neon.kde.org/user focal/main amd64 Packages 5.19.5-0xneon+20.04+focal+build8 1100 500 http://archive.neon.kde.org/user focal/main amd64 Packages 5.18.5-0ubuntu0.1 1100 500 http://pl.archive.ubuntu.com/ubuntu focal-updates/universe amd64 Packages 5.18.4.1-0ubuntu1 1100 500 http://pl.archive.ubuntu.com/ubuntu focal/universe amd64 Packages

Package: plasma-discover

Pin: version 5.1*

Pin-Priority: 1100

/etc/apt/sources.list.d/neon.list looks like this now:

deb http://archive.neon.kde.org/user focal main
deb-src http://archive.neon.kde.org/user focal main
deb http://archive.neon.kde.org/release focal main
deb-src http://archive.neon.kde.org/release focal main

$ pkcon update Getting updates [=========================]
Finished [=========================]
No packages require updating to newer versions.

pkcon update neon-settings-2 Resolving [=========================] Package not found: neon-settings-2 Command failed: This tool could not find the package: No packages were found

$ ls /etc/apt/preferences.d/99-plasma-discover /etc/apt/preferences.d/99-plasma-discover

Or:

$ sudo apt install neon-settings-2
Reading package lists... Done
Building dependency tree       
Reading state information... Done
neon-settings-2 is already the newest version (0.4+p20.04+git20201012.1101).
Starting pkgProblemResolver with broken count: 0
Starting 2 pkgProblemResolver with broken count: 0
Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
$ ls /etc/apt/preferences.d/99-plasma-discover
/etc/apt/preferences.d/99-plasma-discover