Problem
If you go to your Add-ons Manager and you have this message about Xray: "You have unsubscribed from this add-on. The add-on will continue working until the end of your billing cycle. You can now uninstall the add-on from your Confluence instance." Despite this warning, the add-on is fully licensed.
This can happen when a Data Center plugin license is applied.
There is a bug in the Universal Plugin Manager (UPM) that causes this Atlassian Cloud message to be shown in Atlassian Server environments to add-ons that are using Data Center licenses.
This is just a bug with displaying this message, it does not mean that the add-on will stop working or that there is any issue with the license.
Solution
Upgrade your UPM to version 3.0 or newer