Using a multibranch pipeline I see a list of all my Git branches.
However, I would expect git tags to appear in the list also but they don't seem to be listed.
Is this expected behaviour or is this possibly a config issue? Are tags supported? If tags are not supported, is there a plugin that can work in harmony with the multibranch pipeline to support tags?
I think the problem you're facing is described in Jira issue JENKINS-34395.
As far as I understand, the multibranch plugin does not support tags and is focused only in building branches. The workaround suggested is to have two separate builds, one for a normal branch build and second (seems not configured with a Jenkinsfile) to build a tag.
Update, 14.04.2021:
Jenkins does support tag builds now as described in this post but tag builds may not run automatically because of build strategy. Refer to this comment for some details.