Hi @jclausen ... Are these tags missing a leading "5" from the version?

No. That tag is the image version, not the lucee or CommandBox version. The changelog denotes those versions: https://github.com/Ortus-Solutions/docker-commandbox/blob/development/changelog.md

Awesome - thanks very much for the info... I was thrown at first - because there are some previous tags with the full Lucee version in them - and the 3.8.3 just coincidentally, coincides with a Lucee version.