Update on Ubuntu Server 20.04.6 LTS fails to get files...

[Bo Berglund]

This is similar to an earlier thread dealing with Linux Mint, but this is a
non-GUI Ubuntu Server 20.04.9 LTS running headless and accessed for maintenance
only by SSH command line.

I an regularly (manually) doing a system update using these commands:

sudo apt update
sudo apt full-upgrade

Today when I ran the first of these commands I was treated with this (my news
reader wraps lines at about 72 chars so please excuse that):

----------------------------------------------------------------
$ sudo apt update
Hit:1 http://se.archive.ubuntu.com/ubuntu focal InRelease
Get:2 http://se.archive.ubuntu.com/ubuntu focal-updates InRelease [114 kB]
Hit:3 http://security.ubuntu.com/ubuntu focal-security InRelease
Hit:4 http://se.archive.ubuntu.com/ubuntu focal-backports InRelease
Hit:5 https://apt.svtplay-dl.se svtplay-dl InRelease
Hit:6 http://archive.ubuntu.com/ubuntu focal InRelease
Hit:7 http://archive.ubuntu.com/ubuntu focal-security InRelease
Get:8 http://archive.ubuntu.com/ubuntu focal-updates InRelease [114 kB]
Get:9 https://esm.ubuntu.com/apps/ubuntu focal-apps-security InRelease [7,565 B]
Err:10 https://esm.ubuntu.com/apps/ubuntu focal-apps-updates InRelease
  Connection failed [IP: 91.189.91.46 443]
Ign:11 https://esm.ubuntu.com/infra/ubuntu focal-infra-security InRelease
Err:12 https://esm.ubuntu.com/infra/ubuntu focal-infra-updates InRelease
  Connection failed [IP: 185.125.190.24 443]
Get:13 https://esm.ubuntu.com/infra/ubuntu focal-infra-security Release [6,568
B]
Get:14 https://esm.ubuntu.com/infra/ubuntu focal-infra-security Release.gpg [833
B]
Fetched 243 kB in 1min 30s (2,696 B/s)
Reading package lists... Done
Building dependency tree
Reading state information... Done
All packages are up to date.
W: Failed to fetch
https://esm.ubuntu.com/apps/ubuntu/dists/focal-apps-updates/InRelease
Connection failed [IP: 91.189.91.46 443]
W: Failed to fetch
https://esm.ubuntu.com/infra/ubuntu/dists/focal-infra-updates/InRelease
Connection failed [IP: 185.125.190.24 443]
W: Some index files failed to download. They have been ignored, or old ones used
instead.
----------------------------------------------------------------

So there is some kind of problem here too and this time concerning stock Ubuntu
rather than Mint!

What can I do in order to make it work again?


NOTE:

The other thread ended with the poster saying:

"I'm happy to report that the *problem has been solved*!

Bill Stanley"

But WITHOUT telling us *what* he did to solve it!
A bummer which makes me ask again...

I really want to have this server updated as much as possible but cannot at
present do a release-upgrade because it is busy all the time.
Has been running for 10 months now (sice the last power outage):

~$ uptime
 08:42:54 up 300 days, 12 min


-- 
Bo Berglund
Developer in Sweden