Unable to upgrade Ubuntu 20.04 to 22.04 with mirrors.digitalocean.com

sudo do-release-upgrade was getting stuck like this when attempting to upgrade from 20.04.6 to 22.04.x:

Get: 22 http://mirrors.digitalocean.com/ubuntu jammy
InRelease [270 kB]
97% [23 InRelease 20.5 kB/270 kB 7%]

The get for jammy InRelease just got triggered over and over, seemingly never making any progress. It gets stuck at 20.5 kB every time. I’m unsure if the file is corrupted or something?

My release logs in /var/log/dist-upgrade/ end with this and no further information: 2025-09-01 21:59:25,830 DEBUG running doUpdate() (showErrors=True)

I tried using RELEASE_UPGRADER_ALLOW_THIRD_PARTY=1 do-release-upgrade but it didn’t fix the problem at all.

The only thing that seemingly fixed the problem was replacing http://mirrors.digitalocean.com/ubuntu/ with http://archive.ubuntu.com/ubuntu/ in my /etc/apt/sources.list file. If you already tried to upgrade and the sources.list file mentions jammy (22.04) everywhere, you will likely want to first go back to the old version (thankfully stored at /etc/apt/sources.list.distUpgrade) for focal before updating everything to archive.ubuntu.com.

Also worth noting that - in around 2 years after Jammy 22.04 is EOL’d - I believe that the DigitalOcean mirror - when upgrading from 20.04 to 22.04 - will stop working entirely. Just in case this question gets seen by anyone in 2027.

Posting this in case anyone else runs into this, because I couldn’t find anything on the internet about this problem.