Hi Björn,
We are aware that the plugin is probrably not supported at all anymore, but we are using it because it is the official documented way by the Azure Artifacts team to publish maven packages to their artifacts feeds, so that it why we use it unfortunately. If i knew of an alternative way to authenticate using the .m2 file on the computer for maven.publish, I would have done it that way instead.
Thanks for the suggestions disabling the configuration cache, we will try that while raising awareness to the Azure team that they really should be finding/making an alternative and updating their documentation instead of using this very old unsupported plugin.