Docker Engine downgraded when Ubuntu 24.04 reboots

On a new Ubuntu 24.04 LTS server, I installed the docker engine using this process: Ubuntu | Docker Docs

That was successful, shows version 27.3.1, will pull, build and run containers. This is all good until rebooting the server, when the docker engine is somehow downgraded and after reboot shows version 24.0.5. The docker cli client still shows the later version 27.3.1. The latest docker packages originally installed are still installed and pass checks like dpkg --verify. I cannot see where the older docker engine version is coming from. To get back the latest docker engine version, I can apt-get remove --purge the packages and reinstall them. That works and will until the next reboot, when the version goes back to 24.0.5 again. We have not experienced this with our older installations on Ubuntu 22.04 and 20.04.

Have you seen this behavior on your Ubuntu 24.04 systems? What am I missing?

Thank you for any help or advice you can offer.

Scott

You must have installed multiple engines and after reboot, the other starts sooner. Run the following commands:

snap list docker
dpkg -l | grep docker

The installer guide starts with removing docker.io but if you forgot to run that command, the engine you see could be that. or the snap package.

The snap package is more likely since that uses a different docker data root and I believe a different socket, so that could run even while you install a second docker.