ubuntu-release-upgrader, does not update

[ivanto]

:~$ lsb_release -rd
Description: Ubuntu 18.04.5 LTS
Release: 18.04

Lubuntu 18.04.5 LTS distribution does not upgrade to Lubuntu 20.04.1 LTS distribution

:~$ sudo do-release-upgrade -d -c
Check for a new ubuntu release
Progress to the development version is available
only from the latest supported version.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: ubuntu-release-upgrader-core 1:18.04.38
ProcVersionSignature: Ubuntu 4.15.0-112.113-generic 4.15.18
Uname: Linux 4.15.0-112-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.17
Architecture: amd64
CrashDB: ubuntu
CurrentDesktop: LXQt
Date: Mon Aug 31 10:41:57 2020
InstallationDate: Installed on 2016-11-19 (1380 days ago)
InstallationMedia:

PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: No upgrade log present (probably fresh install)
VarLogDistupgradeAptlog:

VarLogDistupgradeLspcitxt:

mtime.conffile..etc.update-manager.release-upgrades: 2020-08-30T11:43:56.501385

[Jouni Mettala (jouni-mettala)]

-d, --devel-release If using the latest supported release, upgrade to the
                        development release

Current development version is 20.10. If you can't upgrade without -d option then please reopen this bug.

[ivanto (ivantu)]

:~$ sudo do-release-upgrade
Check for a new ubuntu release
Download of: 1 Signature of the Version Advancement Tool [1.554 B]
Download of: 2 Version Advancement Tool [1.348 kB]
1.350 kB recovered in 0s (0 B / s)
authentication of "focal.tar.gz" with "focal.tar.gz.gpg"
Authentication failed
Version advance authentication failed. This could be due to a problem with the network connection or with the server.

I cannot update to LTS 20.04 "focal"

[ivanto (ivantu)]

: ~ $ sudo update-manager -c
Check for a new ubuntu release
/usr/lib/python3/dist-packages/DistUpgrade/DistUpgradeFetcher.py:23: PyGIWarning: Gtk was imported without specifying a version first. Use gi.require_version ('Gtk', '3.0') before import to ensure that the right version gets loaded.
   from gi.repository import Gtk, Gdk
/usr/lib/python3/dist-packages/DistUpgrade/ReleaseNotesViewerWebkit.py:33: PyGIWarning: WebKit2 was imported without specifying a version first. Use gi.require_version ('WebKit2', '4.0') before import to ensure that the right version gets loaded.
   from gi.repository import WebKit2 as WebKit
Gtk-Message: 15: 06: 43.225: GtkDialog mapped without a transient parent. This is discouraged.
authentication of "focal.tar.gz" with "focal.tar.gz.gpg"
Gtk-Message: 15: 06: 58.055: GtkDialog mapped without a transient parent. This is discouraged.